Networking issue with possessing pawns if there are two or more clients

(Unreal 4.7.3) I am playing with Networking features and stumbled in this weird issue. Some background: I modified the PuzzleGame template to include multiplayer, created a simple pawn to be possessed by each player controller and added some RPC mechanics. Everything works fine if there are only the listen server and one client, but suddenly things break when there are two or more clients: only the last one of the clients seems to send RPC’s (namely to be possessed by the local playerController). I checked their networking role in c++ and it appears in fact that only one client is AUTONOMOUS_PROXY, with the others being passive SIMULATED_PROXY. Effectively, only one of the clients seems to be possessed correctly.
Some notes: I first tried including the possessing function in my custom PlayerController blueprint, then I changed everything and I called it from the GameMode blueprint for each Controller. Nothing seems to change.
Any idea?

I think I had a similar problem with my multiplayer client\server game. It was not possible to run more than 2 players at the same time and I constantly had “lost connection” error message. I’ve managed to fix it by resetting my config files to default.

To do that I’ve created a new game project using third person template. After that I took all files from Config folder and used it in my project and it fixed the problem.

p.s. Don’t forget to backup your config files before you overwrite it.

It didn’t work for me. I also looked for possible differences between the ‘default’ config files and my files but nothing relevant except specific labels and names.
I’ve read somewhere that networking bugs are known and should be fixed in the next release. Probably my issue is related to one of them.
Thanks anyway!