I think that it is going past the edges of the weir, but I am not sure. I also have a leak somewhere causing the pump to lose prime so maybe the water is circulating back through the skimmer a little when the pump turns off and that causes enough reverse circulation to send the leaves and such back.

I already replaced the strainer o-ring and reseated the filter can when changing the filters a couple of weeks ago. I have one more check valve to check behind the filter....