In my last game I had a Hero locked to a fleet, and the unlocking timer didn't decrease.

Tooltip said the Hero was locked for 16 turns every turn.

The Hero was in a system under negative singularity, I don't know if it can help.

Reproductibilty : 1/5

Expected behavior : unlock timer should decrease every turn

Version : should be 1.0.20

Sounds like a stasis singularity which completely locks a system, fleets, and heroes.