Quote Originally Posted by Ozzblf View Post
I checked my account status on the mogstation and I saw that the time period to play was expired.
After re-sub for 90 days and wait 30 minutes, I'm be able to login again, saying that i have 120 days to play.

So it seems that the free 30 days gifted after the ENDWALKER launch are not working for Steam players, or at leas are not refected on the mogstation, and the verification that steam runs trough mogstation account status return KO, and for that reason can't login.
Unfortunately this isn't the issue, considering myself and several others definitely have subs that aren't on the Free Trial, and probably haven't been in the the last few years. Glad to see it worked for you though!