Poor suction after storms

[Rmleboeu]

I'm stumped, and need help. I have a 20k gallon concrete in ground pool with 300lb sand filter. I have three suction lines: skimmer, main drain, and pool cleaner (I use heyward). I inherited this pool about 7 months ago, and all suction lines ran open at the same time, and I had about 16-18 psi...then a hurricane sat on top of us for three days and a few months later, we were hit by a strong windstorm...needless to say, there was a ton of debris issues.

After the hurricane, I was able to clear all the debris, and get the water back to the right balance, but the pressure was lower (about 14-16) and I was never able to get all three suction lines working at the same time (i.e. In order to run the pool cleaner, I had to shutoff main drain and skimmer, and it ran at low pressure dispersing more water than it was taking in). I checked pool cleaner, but it ran fine on skimmer port, so I know that was not the issue. After the windstorm, the pressure dropped to below 10, so I changed the sand and cleared the impeller. I was able to get my pressure back, but I am still having issues with getting all suction ports to function simultaneously, and when I run the pool cleaner by itself, the filter basket fills with air because the jets disperse more water than the pool cleaner takes in (I know it's not air in the hoses because I already got brand new hoses and primed them with water before starting).

Can anyone else think of any troubleshooting options before I have to pay to get the pool cleaner line checked for cracks?