when i was on a server i had a bug i couldn't use the shift button in my inventory for building in a mini game build it! on a popular server.
so i went on to my world still didn't work it took me a while to clear my full inventory what i had to do is through it in lava which is sad to do. So in my minecraft i have a shift click inventory bug sorry if this inturupts your time sir/ma'am. hope you could find a solution thanks.