An activated behaviour pack I paid for and have used for months suddenly disables achievements

I paid for a behaviour pack (add-on: Realistic Biomes by Oreville Studios) on Marketplace months ago, have never been in creative and still had an ability to earn achievements in my 2yo world - until the latest automatic update from 1.21.73 to 1.21.80 immediately disabled the ability to enjoy an add-on I paid for - if I wanted to continue earning achievements.

There was never a disclaimer that downloading any behaviour pack when I paid for it, that it would ever affect the settings of your world - permanently.

I would like my money back or re-enable achievements on pre-1.21.80 purchased behaviour packs to continue enjoying what I paid for please.

I very, very rarely purchase or even download the free add-ons, because I enjoy the game with very little change/enhancements. This has affected my motivation to ever purchase/use any further downloads at all now that they may be affected by updates, if this is not reversed back to how it was in 1.21.73.