I noticed my MBP had a periodic stutter sometimes: every 3 seconds or so the mouse would lock up for a few milliseconds.

I tracked it down to American Express's login page (auto loads if you leave the site idle) relying on Akamai's anti bot measures polling some web Bluetooth feature, causing Chrome to trigger a BT scan: https://castle.io/research/fingerprint-harvesting-in-the-bot...

Turning off Bluetooth solves it, but that's not a great solution when using a Bluetooth mouse... and it sounds like it might be causing your issue too.