Inventory issues.

[Michel Baie]

I often can't swap equipment no matter what, and there's no explanation why.
Happens randomly, I first noticed it when trying the F-rank hard mode challenge. Restating the game allowed me to change equipment.
It then reblocked me some runs laters while I was trying to swap rings. after I swapped one.

[Eggplant]

I've been having this bug too. It seems to happen after completing or leaving a run, and requires restarting the game to fix it.

[Rhagon]

I'm having the same issue. Maybe it's because I'm playing in Hero mode which blocks equipment swapping while in a run. Could be a flag left over after the run is finished.