It might be worth doing a search for Simon Lemay’s posts where he talks about how large payloads are handled.
You could take the easy way out which I do and set the Max Payload Size to some arbitrary high value for now until the error goes away and then come back to the issue later.
I have a very large network list of structs that on game start take a long time to reach the client and I’ll need to find a solution to that at some point.