we have 10000 on TestFlight, do you do encrypted mutes?
I think Damus is still using the old kind 30000 mute list which has been deprecated and everyone is standardizing on 10000. We are using 10000 in Nos. See https://github.com/nostr-protocol/nips/blob/master/51.md#deprecated-standard-lists
Discussion
Damus 1.9 imports muted list from nos without trouble