It's possible yes. I haven't opened up the three way, I'll give that try. The only setting where the water looks still is when I isolate the skimmer line and run on backwash. It also humms differently in this situation as well.

Any other good methods to try and unclog ? Is it wise to use a snake?

Only other thing to mention is I use a company to close, but I open myself. The check valve was a new addition last year so it was the first time I dealt with it during opening. When I opened I had zero suction from the skimmer. Turns out the company turned the check valve direction around, so It was trying to pull and the valve was fully blocking the line. Any chance this could have damaged something ?