According to the Valheim Discord, there are some known issues with crossplay (playfab) services, so I'm going to shelf this for now until the bugs get ironed out. Apparently as soon as crossplay is enabled, Steam and Gamepass clients are unable to connect to the server, and when crossplay is removed, Steam clients can connect fine...Gamepass clients not so much. Still unsure why my Windows server worked, however I didn't leave it running very long and just tested Gamepass client connectivity briefly. BTW I also tried running a server through Pterodactyl, and in the console logs, this keeps repeating indefinitely:
10/01/2022 19:54:20: Game server connected
10/01/2022 19:54:44: PlayFab disconnect server 'My Server' from network
10/01/2022 19:54:50: PlayFab reconnect server 'My Server'
10/01/2022 19:54:50: Server 'My Server' begin PlayFab create and join network for server
10/01/2022 19:55:14: PlayFab disconnect server 'My Server' from network
10/01/2022 19:55:20: PlayFab reconnect server 'My Server'
10/01/2022 19:55:20: Server 'My Server' begin PlayFab create and join network for server
10/01/2022 19:55:44: PlayFab disconnect server 'My Server' from network
10/01/2022 19:55:50: PlayFab reconnect server 'My Server'
10/01/2022 19:55:50: Server 'My Server' begin PlayFab create and join network for server
Came across this Reddit post as well, but unsure what this means in terms of Unraid and tbh is a bit beyond my knowledge:
If you have any other suggestions, please let me know. Thanks!