Trackpad drag lock no longer works under Mojave

I thought I would update anybody in case they also run into this issue. After contacting Apple support and visiting my local Genius Bar in Sydney, I was given a new MacBook Pro because my original laptop would not boot off an external drive for further diagnostics. When I upgraded to Mohave after taking the new MacBook back to my office, the same problem immediately returned (on what was a fresh install)!

I have continued to work with Apple support, and also contacted the US based Accessibility and Assistive Technology Support group – they have all been excellent and patient, and we are still trying to isolate the exact nature of my problem. After lots of experimenting with the trackpad and accessibility settings, I have found the problem. I am just waiting to hear back from Apple support to see if this is a bug or a new implementation on how "dragging with drag lock" is supposed to work.

Because I am a quadriplegic, my fingers are curled up and I actually tap the trackpad with the knuckle of my middle finger. It is quite a delicate tap, but it still registers when I have “tap to click” enabled quite consistently. When I go into the accessibility settings and turn “dragging with drag lock” on, the sensitivity of taps for “tap to click” dramatically decreases so that even regular tapping doesn’t work for me – I need to actually click the trackpad to get it to register. If I just tap the trackpad, I am lucky if 1 in 10 taps are recognised as clicks.

I believe it is the above software change/bug in Mohave that has impacted my ability to use “dragging with drag lock”. Because "dragging with drag lock" begins with a double tap, requiring the user to hold down after the second tap, the odds of me successfully "dragging with drag lock" dramatically diminish. That is why I thought the feature was broken. I asked a work colleague to test my trackpad with "dragging with drag lock" enabled and it immediately worked for them.

When I leave "dragging with drag lock" off, "tap to click" works very reliably for me. The moment I enable "dragging with drag lock", I cannot use the dragging functionality and "tap to click" no longer works reliably either. When I change the dragging functionality to “3 finger drag”, I can now drag windows (though with less efficiency than my preferred method) and "tap to click" works reliably. I have also noticed that turning on dragging by "3 finger drag" does not automatically enable "tap to click", so these 2 functions are not linked in the way "dragging with drag lock” is linked to “tap to click”. If “tap to click” is disabled, enabling "dragging with drag lock” will immediately also enable “tap to click” since this is an element of the functionality required for “dragging with drag lock”.

Given that dragging is a software feature, it appears to be either a bug in Mohave or an intended change in the functionality of “dragging with drag lock” in order to reduce accidental dragging. My hunch is that I have uncovered a bug, because “tap to click” becomes almost unusable for me only when “dragging with drag lock” is enabled (but otherwise works perfectly).

Hi Stefan,

This is definitely either a bug in Mohave or a purposeful change in behaviour. I will let you know when I find out more – I am expecting an update from Apple support later in the week. Given that they swapped my 2018 MacBook Pro for a new machine, and it exhibited the same behaviour, this is definitely a software issue.

I have been able to replicate the behaviour on my Magic Trackpad 2 and the internal trackpad on the MacBook Pro, so it has nothing to do with Bluetooth settings. As an interim solution, I am using "drag with 3 fingers" which allows me to lay 3 knuckles on the trackpad to drag icons around. It is not as efficient as dragging with drag lock, but it means that tap to click works reliably. You can also drag by firmly clicking and dragging at the same time (assuming you have the dexterity for it).

I will be sharing this thread with Apple support as well – it's good to hear mine is not an isolated incident. They explicitly asked if I knew of another user that was having the same issues, but none of my colleagues have updated to Mohave yet. You've helped verify I'm not alone!

Regards,

Chris.

Thanks Joseph,

I tried resetting the NVRAM but drag lock still does not work. I know that I successfully reset the NVRAM, because after the reboot my brightness and volume were back to their defaults (I had them both on maximum before the reset). I also re-enabled drag lock in the Accessibility settings.

I have a 2018 MacBook Pro with the T2 chip, so I don't know if that makes a difference (I saw in the support document that there appears to be a difference in the way NVRAM is stored on Macs with a T2 chip). I also followed the advice of Mike below and deleted my Bluetooth preferences file, together with the listed Bluetooth accessories, to no avail.

I have tested both my Magic Trackpad 2 and the MacBook's internal trackpad – neither allows drag lock now that I have updated to Mojave. This definitely feels like a bug that others may be experiencing? It affects my productivity, though DragonDictate works much better under Mojave!

Regards,

Chris.

Hi Jeremy (again!),

As an update, I installed a fresh version of macOS Mojave and drag lock still refused to work. I contacted Apple support and we tried a number of things which have still not resolved the problem (I even tried installing the latest Mojave beta to see if that would help). I am booked in to see a specialist at the Apple Store tomorrow, but I am guessing there are issues with the T2 chip that I have run into.

After the support call I tried doing an Internet recovery by booting while holding the option key. It allowed me to install High Sierra, after which drag lock worked. The moment I updated to Mojave, again on the fresh install with no additional software installed, drag lock stopped working. Something strange is definitely going on, as I tried enabling drag lock on 2 MacBook Pro machines in the Apple Store and it worked (they were both on Mojave). Apple support also tried this on a 2018 MacBook Pro with Mojave installed, and drag lock worked for them.

I will let you know how the Apple Store visit goes. Somehow I think they will end up replacing the machine…

Chris.

Hi Stefan,

I actually went to www.apple.com/feedback, which is where Apple support told me I could also report bugs. I previously installed the public beta, but it made no difference at the time, and I don't want to install another public beta until Apple support gets back to me.

Once I get more feedback, I will let you know. It definitely feels like we have encountered a bug which doesn't appear to affect all MacBook Pros the same. I have tried enabling drag locking on a couple of MacBook Pros in the Apple Store, and it worked consistently on those machines. They were running Mojave, but the in-store machines seem to run a demo build which may have slightly different software.

Here's hoping we get a fix soon!

Chris.

That's exactly the problem I have, though it took a while to work out exactly what was going on! It definitely sounds like a software bug – hopefully the next Mojave release fixes it.

Chris.

Thanks Mike,

I tried following your advice but it has not made a difference. I also tested my internal trackpad, as this is a MacBook Pro (2018), and it exhibits the same behaviour. Given that the internal trackpad is not Bluetooth, I suspected this wouldn't solve the issue but gave it a try anyway!

I appreciate you taking the time to offer your advice. For some reason I think this is related to the T2 chip in my MacBook, as this is a relatively new machine and few people enable drag lock. I am guessing this is a bug that was not picked up before.

Regards,

Chris.

Hi Jeremy,

Thanks for the suggestion – I'll give it a try on the weekend since it will be a big job! Thankfully I have a time machine back-up, so it shouldn't be too painful. I'll try on a fresh install of Mojave and if the issue continues, I'll feel confident it's a Mojave bug.

I might drop by the Sydney Apple Store and see if I can replicate the bug on a 2018 MacBook Pro later today. If I can, then I'll save myself the trouble of starting from scratch. I'll let you know how it goes.

Regards,

Chris.