I saw something similar happen to someone else, so I might have your answer.

Sign up for Long Live the Queen (Or to anyone else having this problem, the farthest guildhest you have) and when it’s been successfully completed make sure you talk to the NPC at the end. Do not leave the duty. Let everyone talk to the NPC and let the game end the duty.

I had someone not be able to unlock guildhests because they didn’t talk to the NPC at the end and let the game end the duty after.

Make sure you don’t hit leave or exit the duty through the red line or even talk to the NPC twice to leave as some or all of these may create the problem you have.

The good news is once they are all unlocked every class has them as long as they are the proper level.

Good luck and I hope this works for you : ) Happy adventuring!