My Legion Remix toon abandoned Legion: Remix at L40 and did World Quests. Toon has now hit L80, and I have tried several times to convert him to a Standard toon by clicking on the Hourglass next to his name at Log on, and it doesn’t convert. Any ideas? Thanks in advance for your help! 
As far as I know the only thing that could be preventing it is the 24 hour cap. It’s either a cap on 24 hours after your character is created that you can convert it, or 24 hours after a previous character has already been converted, I can’t recall which.
But if that’s not the case for you at all, I’m honestly not sure, might be ticket time.
I’m having the same issue and my toon was created the first day that Lemix was available.
Ticket submitted, will advise…