It's not your Magic Mouse it's your WiFi Cable and or card
MacBook Pro 13" Unibody Early 2011 AirPort/Bluetooth Board
Answer to "Trackpad suddenly over is sensitive"OK, I've got a solution to Random-Cursor-Jumping that's inexpensive and seems to work as well as my best solutions to date, but this is low friction. Teflon sheet for heat press transfer. I got 3 sheets 16 x 20 for $6.75 on Amazon. (I tried most of the things above, they didn't work for me.) One layer over my 2017 MacBook Pro 15" oversized over sensitive track pad. I just typed for an hour and not one random cursor jump! (Most recently I had 1/16th inch teflon, but it wouldn't lay flat and was expensive. I've been working on this for months. Most solutions I've found are are not slick enough for finger gestures, this is. ) It lays flat, attaches with scotch magic tape, thin as a manilla folder. On the less plus side, it's brown, and has a slight texture. So yo! my 2017 MacBook Pro now works better than Tim Cook's. It's also called "Teflon baking sheet " so maybe there's some in a kitchen near by..... Hope this helps. (And I apologize in advance if I've just solved a problem that a software patch fixed last...
Answer to "Trackpad suddenly over is sensitive"It's been three months since my initial post above. None of the listed tips worked. What has worked is covering the track pad with enough layers of plastic to desensitize the surface, but not so much that the track pad doesn't work. I used lamination sheets one sheet tucked inside another (so 4 layers) then run through the laminator. Only problem was the surface has too much friction. At the moment I have a trackpad 'skin' (total waste of money) and a white plastic (pvc?) new car dealer license plate insert. This has a nice slide, but I do get an occasional random cursor jump. The track pad still works fine. Any other 'solution' than covering the track pad did not work, though it might seem so but not for long. Doing nothing or using one of these other methods: I got a random cursor jump every minute or two. (Apple also replaced the entire machine, though no hardware problems showed up in the tests. Both machines acted exactly the same.) It made writing nearly impossible. I can take these plastic coverings...
Answer to "Trackpad suddenly over is sensitive"The diagonal thing, didn't solve the problem. It might have helped, but that might have just been wishing. This actually seems to work (12 hours ...) https://www.laurivan.com/fix-crazyjumping-cursor-on-a-macbook-pro/ Go to System Preferences > Accessibility > Mouse & Trackpad Check “Ignore built-in trackpad if external mouse is present” Play around for a bit with your mouse, say 15 seconds Come back to the preferences tab and uncheck that box. Commenters say they used USB mice, I've got a wireless mouse (did it with or without, did it different wireless mice) I've had this problem since I first received my new MacBook Pro two weeks ago. I'd been searching for overly sensitive track pad. Yesterday I searched for MBP cursor jumping all over the place I found threads leading to this tip. One commenter said he received this fix from the Genius Bar