I don't know exactly why, and have failed to find a satisfactory answer, but Bluetooth on Macs (as in all(!) Macs, from mini, to Mac Studio, MacBook Pro, any chip, any price) works fundamentally different than Bluetooth on Apple's mobile devices, like iPhone, iPad, Apple Vision Pro, etc.
It's also irrelevant whether your devices are all Bluetooth 5.0 or 5.3.
Most importantly, Mac Bluetooth is just worse at everything compared to Bluetooth on iPhones and iPads, from auto-switching, to signal strength, to the number of devices that it's possible to send and receive to.
I've discussed this topic in a lot of forums but found no true, permanent fix. Only a few workarounds that may or may not remedy the issue temporarily:
- Try resetting your Bluetooth module. You open up the Terminal app and type in "sudo pkill bluetoothd" hit the return (enter?) key and are prompted to enter your Mac user account password. Enter the password and your Macs Bluetooth radio will temporarily disconnect for 2 seconds and then reconnect. For some this fixes the issue instantly, although rarely permanently.
- Disconnect and shut off all Bluetooth devices except your (Bluetooth) mouse. Use the mouse for about 2 to 30 minutes until you can move the mouse around without any stuttering and lagging. Then proceed to add back the other Bluetooth devices.
- Limit the number of Bluetooth devices you use with your Mac's internal Bluetooth down to no more than 2 Bluetooth devices connected at once. This means you run as many of your other devices through Logitech's Unifying or Bolt dongle, or other external Bluetooth receivers, and only use your headphones and either 1 bluetooth keyboard or 1 bluetooth mouse directly connected to your Mac's built-in Bluetooth.
These aren't official recommendations by Apple. They claim you can connect up to 7 Bluetooth devices to at Mac at once while noting that it depends on the specific devices and conditions. Probably not frequently transmitting devices like Bluetooth headphones or mice. Who knows. But since they have never addressed this issue, and so many(!) seem to run into Bluetooth lag issues on Macs, I wouldn't use anymore 2 devices at once.