Yes. Got rid of that after another hand full of tries. I first confirmed the server i want to change to -Ragnarok- (and had some troubles with that button aswell) but at one point the Mogry Station still remembered Ragnarok after the browser refreshed itself automaticly and then i was able to pick the server i come from.

Basicly: Yes. Just keep trying. Your old server should eventually pop up after the new one is confirmed.