Even in a single player world, I still pick up stuff automatically after 1-2 seconds, right click pickup and the Item Filter works as intended.

Have tested with a setup that uses minimal mods only for performance increase like Sodium.

This is also a problem with 1.21

Confirmed. Would really love to see this fixed, as it's genuinely a great feature in combination with the other features this mod offers! :-)

1.21 still broken for this feature

Confirmed still broken in 1.21.1. Please fix this!