Can't access Chromie Time despite supposedly being eligible based on Web research

My level 30 highmountain tauren can access Chromie and Timewalk.
My L46 tauren can also Timewalk. My level 15 troll cannot. The troll has the “Welcome to Zandalar” achievement and has completed the “Speaker for the Horde” quest and still can’t Timewalk. I have 4 level 60+ characters, two of whom started at level 1 and were never boosted. The highmountain tauren and regular tauren can Timewalk…why can’t the troll? Based on web research this seems to be a bug.

Chromie says: “You’ll need to become more familiar with the present before you can visit the past. Maybe I can send you back once you’ve toured the city and met with the warchief!” Going to the warchief in Ogrimmar results in no cutscene.

Any help is greatly appreciated.

Link to failed help attempts below. Thanks in advance!

Unlocking Chromie Time - Guides / New Player Help and Guides - World of Warcraft Forums (blizzard.com)

Have you tried this?