I removed that relay and cleared cache and force closed the app, but I could still see the post. Then I wondered if it might be my local Umbrel relay since i manually broadcast the post to all my relays, which would include that one. So I turned off my vpn which disconnected me from the Umbrel relay and could no longer see the post. Reconnecting to my Umbrel relay made the post visible to me again immediately. Which is odd because the Umbrel details shows that it supports nip09.