This was a weird one, because it's seemingly random. Most of the time, everything would work properly. But sometimes...you wouldn't see the new conversation or reply. Very strange.

It's a Redis key eviction issue because memory was filling up. So I would think the issue is fixed, and then I'd check Redis a few days later, and evicted_keys would be massive.

I've done a bunch of cache tweaks over the last day that I'm pretty sure solves this issue. I'm going to monitor Redis every few hours today to see if memory usage balances out.