It looks like this logic is invalid:

1. We display a subchannel that has no messages
2. We register a thread watcher for it
3. We dispatch an action to fetch the most recent message
4. The most recent message arrives
5. threadIDsWithNoMessages is updated - the subchannel is no longer there as it has messages
6. The effect is called, where we unwatch the subchannel
7. We don't add the subchannel to watched list as it has messages

So basically, we watch for threads that do not have messages and fetch messages for them, but when the messages are there, we unwatch the threads.

The solution to this would be to find a different condition by which we choose which threads should be included in threadIDsWithNoMessages

It's not related to this diff, but we could do something similar for threads in which the most recent message is more than 2 weeks old. Currently we show no messages in that case.

This should be defined closer to its usage (effect)

Should we also check if these are in subchannelsIDsNotInChatList?

Move these closer to their usage

Right, it is not necessary here. I was suggesting a fix for the current state where on login we only fetch recent messages and display no messages on thread list where the most recent message is old enough. We could dispatch this action for them after the login is successful. (This is not related to this diff)