Steps to reproduce the issue

Enable the AdminTasks module in the Module Manager
Create two Task-Categories (Cat-a & Cat b) in the component.
Assign 'Cat-a' to the existing module.
Create a new AdminTasks module and assign it to 'Cat-b'
Set list count at 5 (default)
Create enough tasks to test. Assign half to 'Cat-a', half to 'Cat-b'

Expected result

The original module should only show tasks for 'Cat-a'
The new module should only show tasks for 'Cat-b'
Each list should be 5 items long

Actual result

All tasks are appearing in both modules
Count set to show 5 items shows more

Images of misbehavior

System information (as much as possible)

I can verify that this is happening on a couple of my sites that were built in J! 3.3.6 and updated to 3.4.1 via the updater. I haven't had time to test on a fresh 3.4.1.

Additional comments

Can anyone else replicate this issue.