Have an FC member going through this exact same problem right now that's a PS4 user as well. Character data can become corrupted server side. He filed a ticket with SE's support and they "restored" his character where it again shows up on his log in screen but he is still unable to log into the game on said character, nor does it even show the character in his account on mog station anymore. After trying to contact customer support further they dropped the matter...FF14's customer support is horrid in handling this issue, wish you the best of luck on getting your character back.