Messenger conversation disappeared from phone, briefly showed on laptop, then vanished — what could cause this?

I’m trying to understand what happened with my Messenger chat because it felt really strange.

A conversation on Messenger disappeared from my phone completely without me intentionally deleting it. I didn’t archive it or remove it on purpose — it was just gone.

Later, I logged into Messenger on my laptop and the same conversation was still visible for a short time. After some time, it disappeared there as well.

So the sequence was:

Phone: conversation suddenly gone (I did not delete it)

Laptop: conversation still visible at first

Laptop later: conversation also disappeared

Now I’m confused about what could explain this. I’m wondering if:

It was a sync delay between devices

A Messenger cache/loading issue

A server-side update or glitch

Or if someone else had access and removed it (though I’m not sure how likely that is)

Has anyone experienced something like this before where a chat disappears on one device and then briefly reappears elsewhere before syncing out completely?

I’m trying to figure out if this is normal Messenger behavior or something I should be concerned about.