Achievement not updating mount count

[Nobully-blackrock (Nobully)]

i had an issue with my last mile-stone.

i reported it, but… yeeeeeah.

here is what happened with me

@Nobully-blackrock

i have the highest mount count on my paladins.

got 3 class mounts on a paladin, watched the achievement tick 297, 298, 299…

then went and learned:
Brinedeep Bottom Feeder and Ratstallion on another character.

logging back to the paladin, it didn’t change the mount count.
(also logged other paladins, warlock, engineers/tailors just as a precaution)
achievement count stayed at 299.

Did a 100 badge grind on the paladin to get Argent Tournament mount.
…the achievement for 300 mounts popped, and the mount count instantly went from 299 to 303.

the game needed the mount to be LEARNED on the highest mount-count character for them to register toward the total, and refresh the count.