I noticed this too. I read the little banner of fine print on the promotion calendar page that said something about it will reset your prices to the average (of past several months?) to ensure the discount is off of a base price that is representative of your listing. It is obvious that it was meant to prevent hosts from jacking UP the rate first and then running a promotion.... like a fake sale off of inflated prices to get attention... but the irony is it corrected yours and mine in the opposite direction creating the exact effect they thought they were avoiding. There is nothing you can do about it. Except choose a higher percent discount off the elevated rate.
Basically things are slowing down so our rates are indeed set lower now than they were 3-6 months ago but those high rates are still being considered as normal by the AI. And choosing a promotion makes the AI rope in the old high rates.
For what it is worth, ALL the promos on the different sites are wonky like this. Half the time on VRBO it is also telling me to raise the rate as a suggestion to get booked. The main reason to use the promotion tools is to play the game and get higher rankings on search results. I think the sites like it when users opt in to their "tools"
