So, this 2019 game ended up broken by 2021 where multiplayer saves can no longer be loaded. Also keep in mind that during play for the first year the game was quite unstable where players would often get a message saying game data unstable, load save from most recent load.

Devs have not committed to releasing a patch other than maybe offering a fix for people who buy the next released add ons and this was like 6 months ago.

I've seen many people inquire about it where devs never responded.

(and about questions of stability of saves OS win7/10, lan/wan, fresh OS install, updating/back graphics drivers, have no effect, best we can tell is maybe having more updated C++ redistribution might play a roll.)

Yes the multiplayer is broken but only in longer game such as over 150 turns.
Why? There is a bug in the system.
Why are the Devs refusing to fix it? They aren't refusing, they just don't have the time while they are under contract to develop a game for a publisher (slitherine) and once some time frees up they will look into the cause of this bug and fix it if they can.

Next time please do a little more research and not jump to conclusions.
Thank you and have a nice day.

It's still early game at 150 turns, unlikely to get the lowest level of gear and boat over to mainland to make a base before turn 100. one might have all the fist level stuff unlocked research wise come turn 150.

Having a reason for refusing to patch is still refusing to patch. This has been an issue for almost a year now.(8 months for me), this isn't an old game, came out 2019 and wasn't stable for a very long time. Think it was 2nd to last patch where I didn't have to save every turn (at least in multiplayer)

I am not jumping to conclusions, and I did do more than a little research. This is the consensus of the people in their discord channel. At most they said is they might include a fix with a DLC sometime in the future and that was back in Feb IIRC. With it being a DLC it also brings up the fact it might cost extra to get the patch.

We've also captured a turn that can be loaded by the very next turn which can not. We also tested this in Win7 which hasn't received patches from when game did and did not work. (only changes we can think of is the C++ redist or the date.) But since the devs are not interested in doing anything we stopped trying to pin down the problem for them.

My post is 100% correct in pointing out this recent game is currently unsupported with a known critical game braking bug.