@Synthfox thanks for the report!
This may be possible if there’s some noise coming from the joystick - if the ADC sees two different analog-to-digital converted values in short time, it will send a CC update.
As you wrote it got worse over time, i think your joystick pots may be gathering dust.
You may know this behaviour from some synths (Alesis Andromeda A6 being a prominent example), where scratchy pots can send lots of unwanted updates.
Also, as the MatriX joystick is much more sensitive than the sliders, this is more likely to happen here.
But: as we want to do better than the A6, i am thinking of adding a software filter to the SEQ v4+ mode of MatriX - this problem should be entirely solveable in software - i’ve put this on the list.
The test screen showing reconnects is normal - this better visualizes the 5 second “heartbeat” between SEQ v4+ and MatriX which would otherwise not be shown - we’re implementing TK’s BLM16×16+X protocol which works identical - during normal operations there is no visible dropout as the reconnect happens instantly, while the MatriX is still connected to SEQ v4+.