Steps to reproduce:

1. Give yourself a chest.
2. Enter spectator mode.
3. Set your flying speed to the maximum.
4. Fly several thousand blocks away (5000 are sufficient in my case).
5. Wait until a reasonable amount of chunks have loaded in (to confirm that this is not a chunk generation lag issue).
6. Enter creative mode.
7. Place the chest and open it.
8. It does not open.
9. Break blocks.
10. The hand animation does not show.

This did not occur in 1.21.1, regardless of the chunk generation lag. Note that, for example, animals behave normally while the player is in spectator mode, but stop moving when the player switches to creative. This means that the softlock occurs only because the gamemode is switched.