After updating my iMac to Sonoma 14.2.1 my Magic Mouse started malfunctioning

Having the same issues with my magic mouse lagging and just not responding the way it did before Sonoma 14.2. I've tried resetting the bluetooth module, turning BT off and on again, disconnecting the mouse, etc. with no fixes. Super frustrating!

Have been and continue to struggle with the Logic Tech mice. Have struggled with mouse inadequacies for years. Turning off Blue Tooth cuts of user that rely on hearing aids and other devices using Blue Tooth. It will be wonderful if the industry finally comes up with a usable Mouse. I do like the ergonomic design or the M3 mouse. It's the best all around.

I posted this similar issue when I received my new iMac and setting it up. It's jittery, it delays, and suddenly moves or jumps across. Yes I did what is posted. Remove it and reconnect with cable. It doesn't improve it. Something is wrong with Sonoma with MT. Mind you this is a new iMac M3 and no migration from backup.

I can confirm that when connected directly to the iMac with cable or even a passive hub, the Magic Trackpad works flawlessly. No jumping, stuttering, delays. Very smooth. So clearly this is a BlueTooth Issue. Either software or the hardware from the iMac or Magic Touch keyboard. Clearly a direct connection solves Magic Trackpad issue.

Since this update two different Logitech mice and a Magic Mouse exhibit double taps about 90% of the time. I sure don't want to turn off/on Bluetooth - I have several medical devices which are difficult to get Bluetooth working again. Does anyone have any clue if this is going to be fixed

The only reliable action is connected directly to the iMac or Hub connected to iMac. The MT will bypass BT and use the wired connection. It's much smoother and no quirks. You just lose the point of it being wireless. Maybe Apple will fix it on the next update but I wouldn't have high hopes on it. They tend to deal with these things as low priority since it doesn't seem to affect a lot of people so far.

What kind of Mac do you have? I have iMac M3, New, no migration of old data. No 3rd party utilities. The issue started right as the iMac was turned on and setting up Brand new as the iMac wanted to be updated to Sonoma during setup. I should have left it on Ventura.

I have the 2020 27-inch iMac Retina 5k - no M chip, bought it a few months before they announced the mchip :(

I've had this problem intermittently in the last couple years it would happen every so often, but all I had to do was reset the bluetooth module or SMC and it would fix it, but since updating to Sonoma 14.2, the problem hasn't gone away.

I updated from 14.2.1 to 14.4. The mouse is behaving again.