Diablo 2 Resurrected's servers still aren't fixed and may not be for some time.
Diablo 2 Resurrected's online infrastructure is getting hammered right now. Too many people are playing the game and the old server databases simply can't handle it. This has led to seven days of continued instability during peak play times (which is, oddly enough, during the morning-noon EST periods). As a result Blizzard has had to perform emergency maintenance many times, leading to rollbacks and character progression losses.
Now the saga continues. Blizzard is currently making D2R players wait in an online queue in order to connect to servers and join/make games. This digital wait-in-line plan was put into place to help funnel gamers into a more controlled environment versus the free-for-all frenzy that has crashed the databases many times.
So what's going to happen? Blizzard says a fix will take some time because they have to re-architect the servers and how the game connects to said servers. This means we should all expect intermittent downtime, maintenance, and queues for the foreseeable future.
It's strange that Blizzard didn't expect so many people to play D2R when they literally released it on every platform possible...