Then they may have changed something a bit. To reproduce in another way, enable show hidden files, make Bitdefender's real time protection disinfect and quarantine a malware, disable show hidden files and then enable again. This time you probably won't be able to see hidden files till the PC is restarted. Can you reproduce it this way?After each case, my hidden folders were visible (not blocked) and I could enable/disable the 'show hidden files/folders' option.
Perhaps the issue might occur in case of dynamic behavior detection. Or perhaps the issue is now gone