In the past week when I go to add a new reply to a previous DM that I had started with someone, (actually 3 separate people), the thread has disappeared. The only way I can find it is to scroll thru all of my notifications to find the convo I was having with the person.
I know that if a person mutes/blocks/ unfollows then their message(s) will be gone but that’s not what is happening here.
@Ulf
I have no idea if they have that option turned on