When attempting to export, Krita will hang and never finish the action. Due to this, no other work can be saved without exiting the program via Task Manager, which results in lost, unsaved process.
I'm sorry, but this is obviously something specific to your situation. We've had reports where "Controlled Folder Access" blocked saving, but that doesn't make saving hang. Where are you saving to, and in which file format?
I'm sorry, but I will have to close this bug. We don't have enough information to help you, and besides, it is most likely a system setup issue.