I have this same problem. The 4 inventory slots in the top row, from the right are un-responsive when clicked or hovered over with the mouse.. but will fill with dropped items as normal. This has been going on for a few weeks now for me. Opening a chest's inventory seems to solve the symptoms of the bug, but as soon as I leave the chest alone the bug is back.. I am stuck keeping a chest in my hotbar to plop down every time I need to access those slots in my inventory.
I have this same problem. The 4 inventory slots in the top row, from the right are un-responsive when clicked or hovered over with the mouse.. but will fill with dropped items as normal. This has been going on for a few weeks now for me. Opening a chest's inventory seems to solve the symptoms of the bug, but as soon as I leave the chest alone the bug is back.. I am stuck keeping a chest in my hotbar to plop down every time I need to access those slots in my inventory.
1.15.2 vanilla
Realm world