Only certain things can be overridden. Almost everything can be entered in the interview mode. Override blocks e-fileing and voids the accuracy guarantee.
What do you need to override.
For over a decade I have used the override function. I use it to get an estimate of quarterly taxes due, as I'm still working on getting the details entered in turbo tax. The red highlighting of the override makes an excellent flag that is easily spotted, especially when at a high level like the form 1040. So the 'new' behavior (if that's what this is) is not appreciated; if it is a bug, then needs fixing!
I've noticed this too. Used to be easy to use the override function to make temporary changes for tax planning purposes or whatever. Now, you have to follow the data source all the way back and change the number there, if it even works at that point. I've also had trouble this year with adding Supporting Statements to some fields directly from Forms view; shouldn't have to use the Interview mode to do this!