!ask if I play face breaker on a enemy unit and my unit and their unit bounces back to base and then they ready it again, would it still be stunned?

Yes, it would still be stunned.

Recalls to Base don't change the unit's state — damage, exhaustion, buffs, and statuses like Stunned all remain (Rule 458). Readying the unit only fixes the exhausted/ready state; it does nothing to the Stunned status. The stun stays until the end-of-turn cleanup removes it (Rule 423.1.a.2).

The only thing that would clear the stun is the unit leaving the board entirely for a non-board zone (hand/trash), which resets all statuses — but a bounce to base isn't that.