Kerouacaurus wrote:
Yes, of course. It now shows a box asking if I'd like to allow the connection, but when I allow it, nothing happens and no connection is established.
I have found it best to configure the "Allow accessories to connect" with "Always when unlocked". Otherwise I have encountered numerous issues with external devices. Sometimes macOS will prompt again for an existing device, but sometimes those prompts get hidden behind other windows (or end up disappearing). And if a device has to power cycle itself, then it may not get reconnected again without asking once more & the issues associated with that prompt.
I am also using a drawing tablet. What I find curious is that if I log off, the black screen on my tablet starts displaying my desktop wallpaper, but when I log back in, there the display is just stuck at that wallpaper and not working, it is not a solution, but it might be helpful in understanding the bug.
Check that the third party software (aka drivers) for that tablet are fully up to date and compatible with the current version of macOS you are using which right now should be 26.2. A minor OS update can sometimes break third party software (especially drivers) and it can take the manufacturer some time before they can update their software for the new OS update. Unfortunately some of Apple's minor update patches make a major or critical change.
Make sure to do the same for all third party software.....especially any that provide drivers.
The main issue, however, is the USB ports simply not recognizing devices. I used USBToolBox, and when I connect my devices, they appear in the list, but they cannot be accessed elsewhere, such as in Disk Utility or Finder. They are not working either, for example, my drawing tablet (external display with USB and HDMI) is not responding, and the driver isn't loading upon connection.
Make sure you are using high quality cables to connect your external devices. The cables provided by manufacturers are usually just low end barely functional cables....they may work, but it does not mean they work well. This is especially true for your display cables since Apple has made changes to make those devices work better & more reliably, but it requires high quality cables. For a display, the cable must be less than 1 meter in length including any adapters. Search for recent posts by @Grant Bennet-Alder who has some very extensive posts on this forum regarding display cables after the release of Tahoe.
Same goes for USB devices.
When troubleshooting external device problems, it is always a good idea to disconnect all other external devices just in case one of them is causing a problem. Plus try connect the "problem" device directly to the Mac. If a direct connection doesn't work, then try connecting a USB device to a powered USB3/4 hub instead.......sometimes a USB device may need extra power or needs to be a bit isolated from the Mac.
If you are using an external display's USB ports to connect USB devices, then that could be the problem as well depending on the display's requirements for the video signal.....some may require the full bandwidth of the USB cable leaving no room for any USB accessories connected to the display. This is another reason a high quality USB cable is required.
If any of your external devices are using third party drivers to use them or manage them, then make sure that third party software & drivers are completely up to date and make sure they are compatible with the current version of macOS you are using.
