Multiplayer hotjoin is painfully slow and players lag behind

[Cmd to control]

Whenever my friends and I try to play a multiplayer Stellaris game, whenever we are not hosting on a local network, nobody an join anybody else's games. We can find them in the discovery tab, and we can direct join to the game, but the hotjoin is frozen at 0% or moves so slow that it'd take hours for the game to start. When we start a new game, all of their actions has input lag. Once the game starts, we immediately lag behind the host and the game is frozen on a set date.
For some reason, we can run the game perfectly fine when we join in on the same network. However, any player not in the same network as the host faces these issues.
While we mostly run with VPN on (usually runs smoother with VPN in other games), we have played around with all types of VPN setting including trying with it off. None of these strategies have worked.
Are there any solutions for this, other than to just try to get in on the same local network?

 

[AndrewT]

If you are all on Steam, most likely a Steam port or ports are blocked by a firewall somewhere.

In our launcher's Game Settings menu, have all players choose Cross Store MP which uses the external Nakama MP service instead. Is that any better?

Do disable all mods while we work on this please.

 

[Cmd to control]

All mods have been disabled for this (because gigastructures hasnt updated lol). We've just tested it with cross store MP, which runs better than Steam's usual servers, and the hotjoin bar moves at around 1% per second. It's not very fast and we're still experiencing players lagging behind, but it's playable with the game speed at best being around regular speed.

 

[AndrewT]

Okay then, for the Steam MP service issues Make sure all players have opened (NOT forwarded!) the required Steam ports in all their active firewalls (each player may have up to 3; in Windows, in their router, in their ISP)

Steam Support :: Required Ports for Steam

support.steampowered.com

As to it still being somewhat slow under the Nakama regime, I wonder if this is due to one player, maybe the host, having a problem?

 

[Cmd to control]

We'll try to open up the ports and try again later, but after some investigation I couldn't find a way to specifically open the required ports on MacOS, which is what I am using. I'm guessing that just putting Steam and Stellaris in the allowed section should work. As for router and ISP, i'm not sure if it's even an option with my router given the absolute lack of features this thing has.
As for the Nakama MP, I'm the current host and it's not unlikely that the problem is on my end, given the lack of configuration I have over its firewall. I'll have a few other people try to host and have them join each other's games later to see if it's replicated on their devices.

 

[AndrewT]

As for router and ISP, i'm not sure if it's even an option with my router given the absolute lack of features this thing has.

If your ISP supplied your router, they should be able to help you with this. Otherwise, I guess the vendor's support site?

 

[Cmd to control]

I'll try to track them down, but if Nakama works more consistently it might be simpler to use that instead.