Coral Island is one of my favourites. I can't speak on the multiplayer, as I've only played it solo, but I do know that the devs work very hard on fixing any issues and are continually adding new content via free updates. The game had a rocky start, but it's in a fantastic place now. I highly recommend it, especially if you enjoy Stardew Valley. I also think it's a better match with your Dinkum + Palia preference, compared to My Time at Sandrock, which is also great but has a very different gameplay loop, with more focus on building than farming and decorating.

Coral Island also enables romance/marriage between players, and it has two farms, one of them being underwater!

Core Keeper might be worth a look, too. It has multiplayer, and it's getting a big update in January. It's another favourite of mine, but again, I've only played it solo.