I started my first seasonal character for season 8 a while ago and despite playing quite a lot and defeating lair bosses many many times, I haven’t gotten a single mythic drop. The only mythic item I have is from using the few resplendent sparks you can get without salvaging. I’m either bugged or extremely unlucky.
Welcome to the club.
Got my first in S8 today, with a DT RG at 240 para… and it dropped from a tribute!