Question on pulley bolted to dampner loosening up

The only time I’ve seen something like this, the damper wasn’t doing it’s job.
It wasn’t pulley bolts in that situation though....... it was pretty much all the other bolts.

Basically, the bolt is a spring, and needs the correct stretch to keep from coming loose.
The correct torque(stretch) will vary with the grade of bolt.
Over tighten, the bolt yields and comes loose.
Undertighten and there isn’t enough tension, the bolt comes loose.

New bolts, new hardened thick flat washers, proper tq, a drop of blue loctite....... good to go.

If the problem persists, I’d try a different damper.