once in a while after opening a chest, you cannot click any slots in chest at all. It happened in brewing stands before, but I think it got fixed now. But i think its the problem about glitch or lag in server, just like you cannot eat sometime unless you have to switch another slot before you can eat again. (the server and client got different slot states maybe, so that you cannot eat until you have to re-select the same slot again just to make sure both the server and the client match the same states of slot?)
So its just like you said just click on a different slot before selecting on that food slot again simple
And with the chest just exit the chest and reload the chest
ShotGun,unfortunately, reloading chest doesn't work. and I tried many other ways like clicking all the possible slots in other windows such as inventory and amrors without any luck.
POCPlayer,And I got to go back to menu for it to be fixed!
Wait what when I normally encounter this glitch I just do what I said
It just might be your device or something
I play on a PC. The unclickable chest slots problem has happened the fourth times this month for each time I went to a mansion. So far I can only solve this bug by either rejoining the server or teleport to the others.
And also the anvil slots is not clickable at the same time too. But if you are in battle mode and try to change armors, good luck!