This is clearly a software bug. I've been putting up with it for nearly a year now. 

Same 'solution' works for me:

1. Go to Rules. Open a rule to edit but simply resave the rule without any changes.

2. All Rules will be applied to the bank feed and all transactions with a rule will be categorised.

It's a shame Quickbooks has let this go on for so long.

Mac OS 12.4

Chrome Version 114.0.5735.198