I think your misunderstanding what it means to have the server do the possession, you arnt telling the server to poses the pawn your asking the server to make it happen… So you are using the umg to cast to the player controller which then asks the server to unposses you from your current pwn and posses you in the target pawn you just spawned.
Could i get you to make an example in blueprints?
Okay, i’ve made some progress. Does anyone know to possess a pawn through a player controller or is it only possible through level blueprint?