Aside from eastern Germany, I don't think a single former communist country has SSM.
I think Slovenia has it legal, although sources seem to differ.
No, the parliament approved it in 2015, but it was rejected in a referendum. They have civil partnerships, though.
For some reason, i had a false memory that that referendum was anulled for some technicality, but further research finds nothing to support that.
Maybe it was a confusion with the 2015 Slovak same-sex marriage referendum?
The referendum was not valid, despite getting a 95% support among voters, as the turnout did not reach the required threshold of 50%, with only 21.4% of citizens casting a vote.