Hi! The same issue occurs for me after upgrading my project from 2.02.00 to 2.02.03. Just created a clean 2.02.03 project and I can’t set the tempo there, either.
Additionally it seems that, when editing certain other fields that allow keyboard input, ‘0’ is the default value. Even if that field has already been given input before. For example, in the screenshots below, double-clicking a track named ‘Silence’ instantly changes its name to ‘0’ instead.
So far, on my end, I’ve seen it affect track names, destination marker names, and tempo markers. The only difference for tempo markers is that they don’t accept any input you provide, whereas track and destination markers will change to whatever you’ve typed to replace the ‘0’.
Not sure how useful that info is, but hopefully it’s a clue to solving the bug!
Note that you can still set the tempo marker by typing in the full set of expected data. E.g. ‘110 4/4’. Typing just ‘110’ or ‘4/4’ won’t change the tempo marker. You have to write ‘110 4/4’, even if you only want to change the BPM and not the time (or vice versa).