I’ll add my two cents to this. Through Beta 9, I don’t recall having a focus failure. If it occurred it was very minimal.
However both Betas 10 and 11 have suffered catastophic failures (i.e. donuts) roughly halfway through a night’s session.
FWIW, the focus failures have so far occurred at an AF, during a target sequence, rather than following a slew and AF.
I may yet got back to Beta 9 to see if there is any improvement. If I do, I’ll comment on the results.
Mark