It's not just Damus either. I wonder if there's a common cause.
Discussion
It's not cleat what should be done. If the person is reposting someone you have muted should you hide the repost and maybe even quote reposts? Not sure what twitter does here.
Personally if someone reposts something from someone I have muted, I’d expect that content to be suppressed.
The clients are only checking the pubkey of the reposter/booster not the original note. Reposts wrap the original note in it.