What Google says is BS/mis-information most of the time. The art of saying something without saying anything.
Try contacting Google and asking them to manually check your landing pages... but yeah... when Google say something it shouldnt really be taken as gospel Cheers Stewart
Create a new AdGroup and new ads. If possible, make it a different URL. If that is not possible, create a new ad, delete all keywords and add them again. This works 100% of the time.
Should the whole adgroup be deleted or just the ad and the keywords and then make a new ad in the same adgroup and re-add the keywords? And how long did it take in your experience for QS to go up?
All ads in the ad group. When you update the ad (URL) delete the keywords then add them again. QS updates immediately.