Stop Betta getting stuck at the skimmer

You may try lowering the water flow rate into the above ground skimmer and switching more pump power toward bottom suction and let Betta the mobile skimmer do pool surface cleaning. With reduced water flow into the above ground skimmer, Betta should be able to drive by the opening without getting stuck.

Alternatively, you may attach a floater to the skimmer like the image to the right to stop Betta from getting stuck.