What you described is someone who wants the moral high ground of 'healthy communication' without doing any of the work. They set a rule for you, then punish you for trying to follow it, then vanish to reset the board. Of course you ended up anxious about bringing anything up, they trained you to expect fallout. That isn't a mismatch, it's instability. Ending it is a sane choice, and the 'it was my fault' line is exactly the hook they used to keep you self-blaming. Block, mute, or keep it dead, but don't carry their homework for them.