that should be normal.
did you run a higher dosage of caber?
it works on the dopamine receptor.
dopamine is a hormone that makes you feel good, similar to serotonine.
im not familiar with exact interactions, but you can explain it in these simple terms, cabergoline activates dopamine receptor, dopamine makes you feel good.
when there are suddenly less activated dopamine receptors you start to feel not so good anymore

i dont think it has anything to do with downgrading.
so you dont necessarily feel worse than before, but less good again.