We’ve released Copter-4.2.1-rc1 with at least some of the fixes from @andyp1per. I wonder if you could retest using the official version downloaded from MP or QGC?
Now, I’m not tracking in detail which issues are fixed and which are resolved so apologies in advance if this ends up wasting your time a bit. I suspect @andyp1per will correct me if I’ve got something wrong.