The carrots are spending more time in storage. Ethelyne gas from other produce starts a chemical reaction in the carrots that generates terpenoids, aka the soapy taste. This can happen in the fridge but most likely the market is selling older product due to supply constraints or just capitalism.

Holy shit you rule, thank you

Old product gets sold first, so what you are looking for is a demand change that leaves carrots for supermarkets sitting longer. I would look to how delivery vs in-store is affecting the retail demand profile.