I don’t know if this is a bug or not, but for two days in a row now I have queued for TWW Heroic random dungeon, and the first dungeon I end up in is Mythic+ Grim Batol. Its really annoying because its a waste of my time, doing a dungeon I didn’t queue for. (Yes, I could bail, but then I get the deserter buff, and it also doesn’t seem like the honorable thing to do, bail on the group because it’s not the right xpac dungeon.) The second time I queue I get into TWW Heroic like I wanted. I tried to report this through in-game customer support, but none of the CS options seemed to fit?
Update: Today’s second dungeon was Shadowlands. Wtf is going on? Why can’t I get into a TWW dungeon when I’ve queued for it?
The only thing you can do is report it as a bug in the appropiate location
When queuing for a Heroic Dungeon, shouldn’t be going for a Mythic+ dungeon, so this is something new, but would not surprise me if there was a bug in that case. Report it as a bug, and let the QA team investigate.
EDIT: Are you queuing for the dungeon also through the dungeon finder, or through the premade group finder?
Thanks for your reply, I have been queueing for Random Heroic (TWW: Season 1) through the random dungeon finder. I wonder if it’s my iLvl (609) that keeps throwing me into the Mythic+ dungeons? When I end up in the wrong Xpac dungeon and I say “How did I get here?” someone always says, “This is the same as mythic” or “This is the Mythic+ pool”. (So confused. ) I’ll put in a bug report, ty! I thought maybe I was just being funnelled into a different xpac because no one was queueing for TWW (which seems odd since it’s the newest, now that I think about that…) I will put in a bug report. Thank you for your help.
Um, ok. That’s stupid. Why would Blizz do that instead of letting us do TWW dungeons? I really don’t understand. Thank you for the link, btw, that explains it.
They have seasons because it would be terrible if we had to run the same 8 dungeons for Mythic keystones throughout the entire expansion, so they alternate them. You can still run the OG ones through follower/normal.
) I’ll put in a bug report, ty! I thought maybe I was just being funnelled into a different xpac because no one was queueing for TWW (which seems odd since it’s the newest, now that I think about that…) I will put in a bug report. Thank you for your help. 
Thank you for the link, btw, that explains it.