Somewhat of a duplicate of MC-206986 but it's been marked as resolved when it clearly isn't.

Steps to reproduce:
1. make a creative world or go into creative mode
2. set open inventory keybind to "Tab"
3. open the inventory
4. go to the "Search Item" tab
5. button no longer closes the inventory as it should

This wasn't an issue on 1.16.1. Not sure when it was reintroduced.