Soccer's G.O.A.T. apparently has a problem with sheep ... 'cause Cristiano Ronaldo reportedly had to move mansions this month -- after baaing animals on his property kept waking him up!!!

Shortly after departing Juventus for Manchester United ... Ronaldo and his fam moved into a 7-bedroom pad in the UK -- but packed up and bolted to another palatial estate just days later.

As for why, The Sun says it's because sheep on the first property could not stop making racket!!