Plumbing Airlock?

I have a question and wanted to see if anyone has experienced this. I had a valve housing crack therefore the valve had to be replaced. Since there was not much room to play with my pool mainteneace guy replaced and replumbed the skimmer/drain valve and the spa/pool valve. When he replumbed he did it like the picture supplied. Now when pool is tunred on if I turn valve to drian only everything works fine but if i change it to skimmer only or 50/50 I get air in my system. My question is - the way that he plumbed the pump the water line goes well above the filter inlet before it comes back down and then into pump. Is this creating an airlock when I have it skimmer side only? Pump primes but water flow goes from good flow to stop and then back to good flow.

!(file:///C:/Users/standers/AppData/Local/Temp/msohtmlclip1/01/clip_image001.jpg)