When I moved to Yorkshire in the 80s, I had serious trouble understanding my neighbors. Everyone understood me perfectly, no doubt from watching US TV (Dynasty was big in those days), but if I asked a question at the greengrocers, parsing the answer was nearly impossible.
After a month or so I went on a car trip west, and at some point picked up a radio station that sounded just like home. It was an Irish station.
I’ve since lived in Scotland and Norway, but only in Yorkshire did I have real trouble understanding English through the accent.