Can't unshare file because File is locked

Hi, everyone! I'm new to this forum and new also in using VBA. I've made a file with VBA to somewhat automatize our project drawing logbook. VBA related to static date stamping which I refer from topics of this forum. It seems that everything works right, therefore I went to the next level. I protected and shared the file to our network system and try if everything will still work. Almost ok but still requires further refinement.

Now comes the problem, I want to unshare it to edit the file but it's giving a notification that file is locked and also I can't unprotect. Is this due to VBA? Can someone please help me?

I attached the file for everybody's verification. Password is execaps

Thanks in advance.