Ads are meant to be static not dynamic, even if it will be dynamic then they have to prompt it and once clicked there shouldn't be a change in value of what that has been clicked initially.
Sometimes the ad may be changed but it supposed to be of very little difference and it should not be common. Like out of 10 to 20 ads, you may notice only 1 ad changed, but not like it is on Burger that every ads are changing.