I recently diagnosed a very weird problem on my M32 MacBook Pro 13" where the _HDMI_ cable I was using caused my Logitech mouse (with 2.4GHz dongle) to stutter and disconnect/reconnect. Nothing to do with the display, my adapter/dongle, other peripherals, or other running apps. Still don't know _why_ that HDMI caused those issues, because the display was fine, but... MacOS is just sometimes obtusely weird!
Similar thing happened to me with my Apple TV 4K. When I was watching it, Bluetooth devices in the vicinity (including its remote!) became choppy and unreliable. Turned out to be the fault of the HDMI cable! Replaced it and the problems all disappeared.
Possibly... But I don't understand why that particular HDMI cable was causing issues with my USB devices -- with no visual artifacts or latency or other issues being evident on my screen.
But you're right -- I was possibly too quick to snark about MacOS when the real culprit is more likely the cheap random HDMI cable I used. :)
Most likely the HDMI cable has significant signal leakage (poor or missing shielding), and the signal has some component (or harmonic) in the same spectrum as your dongle.
