Cannot become Thane of Whiterun

After becoming Thane of Whiterun once through the Main Quest, this has to be redone when siding with the Stormcloaks in the War. The relevant quest is this one

This Quest is not available to me. Vignar is on his throne, I already purchased Breezehome from his steward. The war is over. The option to start the quest just doesn't exist. And I checked that I am not already Thane with the guards.

I tried every console command I could find, e.g. startquest, setstage, resetquest, completequest. Nothing worked. I tried raising the relationship rank with Vignar. I tried disabling/enabling Vignar. The quest is still not available. This is currently making me not want to play anymore as the goal I set myself to keep playing was becoming Thane in every Hold, which now is impossible.

Does anybody know of other things I could attempt to get this quest started?

I believe the quest you linked only applies if you weren't already appointed as Thane by Balgruuf. If you have bought the house and Lydia is available as NPC, you are already a Thane. And so the quest won't pop up.

I have no idea why the wiki says that your title is revoked, that never happened to me during my numerous play-throughs, no matter which side (if any) I picked. Unless some manner of bug is at play here.

It also doesn't make sense to revoke the title, since the only way for the Stormcloaks to capture the city is if the player sides with them. Why would they revoke a title when you played a key role in capturing the city for their faction?