After adding a price exception in the Price Calendar tab, all discounts and markups (first minute, last minute, length of reservation) were overwritten and not included in the final price. From now on, markups and discounts will also be always included in the final price.
Go to Offer -> Reduced prices, markups and discounts and then check the current Discounts and markups settings in the rate plans. Then verify price exceptions (marked in yellow) in the Offer -> Price calendar tab, because when you activate the changes from the introduced exceptions, discounts and markups settings will be calculated, which will affect your offer.
You don't have to do anything, on 2.11.2020 discounts and markups will be included in your final price. Until then, you can verify your current settings and adjust them to the new calculation type.
If you want, you can start using the new discounts and markups now! Just go to Administration -> Conversions and select the option Include discounts and markups for price exceptions.