(I am playing on 1.20.2 but it wouldn't let me select that version for whatever reason)

If I click on an item in my inventory or container it won't pick up.

I assumed I would be able to pick items up if I left clicked on them.

I could only hold an item if I held down left click.
When I held down left click I would pick the item up but could not hold down right click to place one item back or right click before left clicking to half the stack.

I sadly have no idea how to reproduce this.

I do however have another bug where the arrows that show up on servers constantly show up on all servers in my list. I do not if these two are correlated or not.