Version: Latest (1.19)

If you walk up to a tool belt on the ground with a full inventory (no free slots), while in creative mode, the item gets sucked up to the player (how items usually do when you have inventory space) but it then disappears/gets deleted

This doesn't happen in survival mode, the tool belt stays on the ground as it should

That's a vanilla feature lol. Happens to all items.

oh damn, so it is. Didn't realize. Was never frustrated by having to recreate all my maxed out gear before I guess. Apologies then