I suspect, considering I was having this issue back in January 2019 (two years ago) that they probably don't have an answer if you're still having the same issue now. If you contact the Factory Reset Team they may be able to instruct you to do a Factory Reset. Otherwise as long as the issue remains listed as a "known issue" you should be OK with that right?
Unfortunately at this point in time I've given up on the idea that my mixers will work as intended. The instance of a scene recall corrupting the base routing functions of my SL24mkIII was just about the last straw for me. Of course the factory reset that I was instructed to perform DID repair the issue but that didn't help me until after that show.
Updating the base firmware on my SL24mkIII to the latest - as instructed - has not yet fixed the issue of buttons randomly flickering different colours. I'm still waiting for the metering in UC Surface or UC Control to be even remotely close in timing to the input signal. I eagerly await the day that the Gate Gain Reduction meter in UC Surface/Control represents anything at all (apart from maybe the trajectory of a yo-yo). Still also wondering how many desperate pleas from SL mixer owners it takes to convince Presonus that an offline editor is a valuable(essential) addition...
I could go on but I won't. Hopefully you can find a suitable work-around for your matrix bus problem.