Bluetooth connectivity issues

Having the same issue, making me want to return the Mac Mini. It will disconnect from my magic keyboard and Magic Trackpad periodically. It become worse if I am connecting my Mac Mini to Samsung Smart TV via HDMI cable. (will disconnect every few minutes). Try all the methods all I can find online, still don't work.

I had Bluetooth issues with my new MacMini 2018 from the beginning. The new KB was mostly OK (occasional disconnect, but rarely) and the new Magic Trackpad 2 was mostly OK (occasional disconnect; more frequent than the KB, but not by much). However, my older Magic Mouse was unusable. It was constantly disconnecting and reconnecting, and was really jittery when it was connected. It was worse when an external drive (USB-3) was hooked up and in operation.

I tried all the usual things - securing the batteries, deleting the mouse preferences, etc. Some of those things would work for a few minutes but then the problem would come back. Finally I started thinking about my WiFi router. It's a pretty old Airport Extreme, single band, on 2.4GHz. I've been wanting to upgrade it anyway, so I got a new (non-Apple) dual band router and hooked it up.

End of Bluetooth problems. As long as I'm signed in to the 5GHz network, all devices work flawlessly. If I switch to the new router's 2.4 GHz band, it works OK for a while but soon starts to degrade again.

This is not intuitive. What does the Wifi band have to do with Bluetooth devices? Well, it's above my pay grade, but I do know that USB-3 works on 2.4 GHz, so somehow the Wifi using that band messes up some BT connections. Regardless of why, this solution worked for me. AFAIK most routers are dual band these days so you probably don't even need to buy a new one. Just make sure you have a network on 5GHz and use that.

My Mac Mini has problems with a non-Apple Bluetooth mouse after I play a video with VLC. I leave a wired mouse connected so I can restart the Bluetooth . Ethernet, WiFi repeater bridge.

My older-gen Mini hated non-Bluetooth mice, using the alternate radio frequency dongle. It also hated when the USB connected Blu-ray drive was open (radio interference?).

Aha! Found the problem, using other groups and what I'm doing. Yes, there is a hardware problem. The USB ports on the mini are underpowered, and when too much power is pulled it also drags down the Bluetooth module. The fix appears to avoid USB ports farther away from the HDMI port, and for best effect get a powered USB hub or run USB adappters off the Lightning ports.

In my case, I have a hard drive running off the USB port, which is where my movies are coming from. This drains power from the Bluetooth.

Same!!!

I believe there is a fundamental flaw with the way apple handles bluetooth devices. I upgraded from my 2012 Mac mini, hoping things would be better, and I can't believe it's still having terrible bluetooth issues on the latest release.

Pretty much considering returning it!!! Never had to do this with an Apple product before. These things aren't a reasonable price when you compare to other companies offerings so it's a shame.

It's not the Bluetooth, exactly, it's the power supply which is shared between the USB and the Bluetooth. There's not enough oomph to keep everything running, since USB and Bluetooth seems to share. Suck out enough power to run the USB, and the Bluetooth module goes wonky, resetting when the power drops too low. I put in a powered USB hub (to one of the USB ports) and everything works great now. Is it a flaw? Yeah. Fatal? No, just annoying. Powered USB hubs are pretty common in all personal computers.

Sorry, I keep getting Lightning and Thunderbolt mixed up. Of course, the four Thunderbolt ports on the Mini are really for testing and gaining experience on what Apple is REALLY doing in San Diego, and it has nothing to do with new phone chips...

Yes, I've been experiencing frequent random disconnects from all my BT devices (Apple mouse and keyboard, Bose Soundlink phones). I thought it might be the Bose headphones which have been problematic on other computers, but it does this with just the mouse and keyboard. Mouse and keyboard reconnect usually within seconds, but often the mouse slows down and everything locks up for about a minute. I haven't been able to see anything suspicious in Activity Monitor. I've had my new Mini for 2 weeks, and hoping an update with cure this.

I’ve been working on this issue all day. Turns out after doing all the resetting and removing of devices etc, the thing that has worked for more than an hour was changing WiFi router to use 5Ghz only frequency. Might be too soon the open the champagne, but it’s the best it’s been.

Again, please make sure you have NOTHING plugged into the USB. Apparently there isn't enough power to run both the USB and the Bluetooth at the same time. I fixed my problem with a powered USB hub, and the Bluetooth works fine now.

Remember that some wireless keyboards and mice are NOT Bluetooth, but operate in the WiFi 2.4GHz band and will interfere. I have an ancient CenturyLink router with only 2.4GHz WiFi, but I don't want to switch after working for months to get them to fix it... :-)

I connect my Mac Mini to Samsung Smart TV via HDMI cable. (Besides this, there is no other port being plugged in). My Magic Keyboard 2 and Magic Trackpad are connection to the Mac Mini via bluetooth. Both of them will disconnect pretty often (once a few minutes, or a few seconds). However, If I switch my TV to Dell monitor, the disconnection seldom appear. Anyone know why it has such big difference? My WiFi is in 2.4 GHz channel though.

Unfortunately the router I bought only support 2.4GHz. But if WiFI is the problem, I can try using Ethernet to see how it works.

Btw, It suddenly works well (connected to TV), only disconnected once during the entire afternoon.

Just learn a new trick today, would like to share it here, in case someone like me never aware of it....

If you charge the keyboard/trackpad on Mac Mini (connect it with the lighting to USB cable), the keyboard/trackpad will turn into a wired keyboard/trackpad. This may be a temporary resolution.

I just put my Magic Trackpad 2 on a lightning cable wired to my 2018 Mini. The trackpad has been freezing and disconnecting multiple times a day for several days. I'll report if using it as a wired trackpad has any effect.

Since I connected my Trackpad 2 to my Mini I've had on problem with it. I'm not sure that the problem is with the Mini. The Bluetooth extended keyboard and various headphones have no connectivity issues with the Mini; it is just the trackpad for me.