I really need help (like I'm begging, man) understanding why actors are disappearing during multiplay (5.2.1)

I have been looking for help on this for a week now and I can’t seem to find any answers or guidance.

I have a simple tile system where the host can spawn/manipulate tiles and actors on them. There is no landscape or anything like that. Clients can join the host on their map, it’s basically a virtual table top simulator.

I am using the Advanced Steam Sessions plugin with the development server (Spacewars) to test the system out (no LAN, two PCs with different IPs). The only other plugin I have is Rama Save System which exclusively works host-side.

No world partitioning, just basic map. Really simple stuff.

At random, either once in an hour or every couple of minutes, the client will experience a portion of the tiles/actors, or even all of them, suddenly unloading. I cannot for the life of me understand why. I have a suspicion it is related to packet loss, but I don’t understand quite enough about that to know for sure. The actors are set to Always Relevant.

I would really really appreciate any help.

Are the tiles spawned or are they part of a static map (persistent)?

If Spawned & replicated you need to ensure their net cull distance is large enough. Default is 50m.