Spectrocoin, Yobit, can't remember when I hear these names last time. It feels like I'm back to 2017.
I doubt that they want to scam you for $18. It's just common thing for centralised platforms, related with various regulations. Considering that money came from Yobit - exchange with terrible reputation, probably it's nothing strange that something got triggered on Spectrocoin side, even though it's little amount. Interesting how this story will develop further.