It's been a while since I last played the game. I think it was before the remake.
The biggest issues I found were all UI related I'm afraid. I'm not allowed to equip a 2-handed weapon without first unhanding the shield, but I could equip a shield right away afterwards. Reloading the game removed the shield from my inventory altogether.
I also managed to softlock the game at the blacksmith by buying a weapon, equipping it, and then directly selling the weapon I had previously equipped without placing it in my inventory first. This made it so left clicking did an attack instead of letting me move. Talking to the blacksmith again hid his store and opened my own inventory.
I can only speculate but it seems to me like you are flipping a bool to open/close menus and this might be causing the issue.
You should consider implementing a button that closes all menus at once. I recommend ESC.
Keep up the wood work.