Yes but when you get to the beta/rc stage you are basically at the code freeze stage and only major bugs get pushed into the code. The beta releases are when you tweak your system and apps and ensure everything works.
This sounds and feels like an API change which is a big no no this late in the game.
A new build can still introduce bugs. Which is what happened here. We’ve seen this happen many years. It’ll be resolved. You’re making this out to be bigger than it is.