Weird Mouse Behavior on 2018 Mini

[N9JIG]

I have had the dreaded Bluetooth issues with my 2018 Mini since I had it and eventually converted to a Logitech MX Master 3 using the Unifying Dongle plugged into my Satechi base. It has worked fine for months until this week when all of a sudden it is having the same issues common to the Magic Mouse (jerky movements, un-commanded relocation of the cursor, etc.).

I had had the Bluetooth on my Mac turned off but somehow it came back on after a restart. I turned it off again, thinking that it would be interfering with the Unifying Dongle (which I assume is also Bluetooth). I restarted the computer again and it still has these issues.

The mouse lives less than a foot from the dongle, the Mini's BT and WiFi are both off and I have not had any issues with the Logitech MX Keys keyboard that shares the same Unifying dongle.

Any ideas?

 

[Wando64]

I don't know what is the "unifying Dongle"
Assuming it is an external Bluetooth receiver, I am also using one with my Mini and I can confirm that after a restart the Mac will (almost) always reset to use the internal Bluetooth.
Reboots/restarts are rare these days. You just need to remember to re-select the external receiver every time.

 

[N9JIG]

The Unifying Receiver is a small USB dongle that is apparently its own RF adapter made specifically for Logitech devices like keyboards, mice and trackballs. It is usually included with most Bluetooth products from Logitech these days. I don't know if they use Bluetooth or a different technology but it does operate on 2.4 GHz (same range as BT) and automatically pairs with their devices.

I have used these on several computers over the years with no issues.