Networking out of sync

I’m having some problems with my round based multiplayer blueprint prototype getting out of sync. I’m testing it locally in PIE with 2 players. One is the server and the other the client. Since it is round based I kept the communication to a minimum which is basically just which tiles the players select which is also all the interaction players can do.

I noticed the getting lots of these messages in my Output Log:
LogNetPackageMap:Warning: UPackageMapClient::InternalLoadObject: Unable to resolve default guid from client: PathName: Tile-BP_C_421, ObjOuter: /Game/Maps/UEDPIE_1_Gameplay.Gameplay:PersistentLevel

Tile-BP is the tiles the players can select and that selection gets multicast to both. That number in the message can vary to all kinds of different tiles.

I have no clue what that message means but it appears to be connected to networking. Could this be the problem and what could I do about it?