Proven Pet Parent

Ya, just got nerfed.

Has anybody else had the problem of this Achievement not completing even when it is completed? I actually achieved this collection milestone I don't know how long ago (I currently have 1711 pets in my pet journal) and have logged on and off probably 1000s of times since I reached pet 1400. I don't know when I collected the 1400th pet, and apparently Blizzard doesn't, either. This Achievement progress bar is stuck at 1382/1400 pets for me. I have not been awarded the frogduck. I reached out to customer support and was told:
"At this time, there is nothing we can do from our side to resolve this issue directly. The best approach would be to continue submitting a bug report so our development team can investigate further. Bug reports are reviewed by the team and help identify issues that may need attention in future updates."
Has anyone had a similar issue and been able to resolve it?