I was out of town for 3 weeks and at some point while I was gone my pump began to struggle to stay primed. The clear top of the basket in front of the pump usually only has one or two small bubbles in it but now it has a pocket of churning air. I can hear the air going through the plumbing and also when the bubbly water returns into the pool (see pic below).
In the past when this has happened I have re-lubed the O-ring on the clear top pictured and that solved it but I have done 3 re-lubes in the past 4 days (you can see the extra lube around the edge!) and it has not helped.
The water level of the pool is the same as always and the skimmer has a normal flow into it as well.
What else might be going on?