Yes I've had it happen. Often it is not as dry & clean as you think in there, not unusual to see corrosion on some components at least. Mine was pushing out 32v & destroyed a pair of batteries after a couple of seasons. I was reassured as it seemed to be so good at charging!
I fitted a brand new panel that was still sealed in its box & that didn't work at all! I plugged in several that I had lying around. The best regulation came from a muddy & battered one that was on the ground at a scrapyard & that was perfect inside!