I have an Apple Magic Keyboard connected to my Mac mini (currently running Monterey but soon to do so under Ventura). When the keyboard connects via Bluetooth it behaves erratically with very slow response, sometime double keying, and others affecting every program. When the keyboard connects via the USB charge cable it behaves as expected.
Is this known behaviour or something weird limited to my system.
No, it affects my system too (with the exact same keyboard as yours). It only seems to happen briefly after I log into my account, but it’s annoying nonetheless.
I’m hoping that macOS Ventura fixes the issue.
You have bluetooth interference it sounds like. Anything around it running bluetooth that could cause issues?
I obviously can’t speak on behalf of the OP, but in my case, the only other “Bluetooth” devices I can think of are my iPhone and my Magic Mouse.
I used to get very annoying issues with my Apple ‘Magic’ peripherals with a 2018 Mac Mini. I mitigated them significantly by repositioning where the Mini was on the desk. It seemed like the distance and whatever objects were in between were causing it serious problems.
The biggest single difference was raising my monitor so there was a clear line of sight between my mouse (the furthest away and worst affected) and the Mac.
From discussions at the time I have a feeling the Mini was generally thought to have inferior Bluetooth performance (perhaps due to the location of the antennas).
Certainly now I have a MacBook Pro (original M1) that sits in the middle of my desk, I have zero problems with intermittent behaviour. Just the “standard” behaviour of one device (either mouse or trackpad) occasionally becoming completely unresponsive until disconnected and reconnected via the Bluetooth menu.
It never crossed my mind that there might be interference with Bluetooth! Should have considered it as I hold an amateur radion licence although been QRT for at least two decades. I do fiddle with the channels on my WiFi router. Most of my neighnours use whatever is default so I go hunting for an un(der)used channel. The Mac mini by the way has a wired link to my full-fibre hub.
My setup is Mac mini on the shelf of my computer desk. Above it less than 30cms on the rollout tray are my Magic Keyboard and Magic Mouse. The keyboard and mouse overlap the Mac mini. On the same shelf is an older Mac mini, which used to run OS X Server/ It is sometimes discoverable and other not.
In addition there can be my MacBookPro (M1), iPad Air (4th gen), and my ancient iPhone 6S. (Lockdown and other issues have prevented me from going to get an upgrade but that will be a 14.) These come and go depending on whether I have been using them while out of the house or in another room.
Looking increasing like my problem is the number of close proximity devices that have Bluetooth enabled.
I have 3 computers all in close proximity, one Mac and two PCs. The Mac is fine, but one of PCs has all sorts of problems trying to connect to anything to anything Bluetooth. Seeing the problem PC is a homebuilt machine, I assume the motherboard has a crappy bluetooth radio and that’s what the problem is. Still, with so much reliance on bluetooth nowadays, I need to move it to it’s own little spot.