Failed to encrypt message to a user in a room

[richvdh]

I have a rageshake where a user on Element iOS sent a message in an encrypted room, but failed to share keys with a specific recipient. It seems the client did not know that the user was in the room.

Weirdly, the same device sent another message in the room shortly after, and included the missing user.

Other than an app reload, it is unclear what could have changed in the intervening period.