Error: Failed to join any instances (during azurite mine)

I can't access most Azurite mine nodes
If I try to delve while in the mine encampment, i click the node i want to go to, the subterranean chart disappears and nothing happens. If I try to do the same when in my hideout the error message appears.
Notice that there are some nodes that do actually work. For example the last node i visited and a couple more.

ref number: 3.565.511.035

https://imgur.com/a/EeO3g1S

So Frankfurt is still not fixed?

It is not restricted to Frankfurt server.
I had frequent disconnects and a couple days ago I switched to Milan server to remedy the ping fluctuations but the problem with the instance still occurs.