I had an issue a while back where my skimmer was producing way to much and overflowing as well. Not good skimmate just a massive amount of bubbles that would overflow everything.
It would do this randomly where it would pull a huge amount of overflow, I could shut it down for just a few minutes and then it would settle down when I restarted and it would do fine once again, it was not consistnet and did it at odd times.
I cleaned it several times and it would still do it, but at odd times. I never did get figured out for sure exactly what was causing the issue, but I disassebled the entire skimmer and soaked in vinegar and cleaned really well and it has not done it since. I did find some chiato that had sucked into the ventura, but I really have no clue what caused it, but it has not done it now for several months. I really hate it when I can not specifically figure out what the issue is!!. Good luck.