Skimmer not holding pressure and sand getting in pool

[Teerump]

Hey guys, opening my pool again, everything was going good, then went to vacuum the bottom and every time I try to vaccum, it works for a few mins, then the skimmer doesn't hold suction and the hose pops out. The filter ran all night last night, skimmer was fine. But when I try to vacuum or when I added a little DE to help clear up the algae, it lost suction after a few mins. And I'm getting sand blowing back in after I backwash. This happened last year and I took the filter apart, checked the laterals, all were good, replaced the spider gasket in the multi-port valve, and I still had sand blow back. I left it for the rest of the summer, but trying to figure out how to fix it. Any help for both problems would be appreciated.
Pool is a 16,000 gallon inground rectangle, vinyl liner.
Filter is Hayward S200.

 

[V___25]

I get some sand after backwashing but not a ton. How much sand? Is it possible there's too much sand in the filter or the wrong type of sand?

 

[wireform]

Pictures of the equipment pad can be helpful. Are you sure you wait enough time to turn the mpv to the next position? Adding de to the sand filter and then trying to vacuum is counter productive. As soon as x amount of dirt gets into the filter you loose the strong suction. and ofcourse the hose will come off.

 

[Teerump]

I tried rinsing longer after backwashing, I believe that helped. I generally don’t put DE in and then vacuum. Thought I would to see if I could “catch” more Crud. I’ve never had it lose suction in years past when vacuuming. My pump pressure when filtering is holding at 25psi, which seems high to me. I don’t remember it being that high before. I’ll try and vacuum again in just a bit. And I’ll get a pic of my setup.

 

[Teerump]

Went back out and vacuumed again, it held suction for a little bit, but there was alot of junk on the bottom. After I lost suction, I backwashed and rinsed a long time. Didn't really see any sand blowing back in. I vacummed again and it held suction the entire time I went around the pool. I did notice my pressure gauge is bad. When the pump is off it's reading 10psi. That would explain why it's reading 25psi when on. Would a bad pressure gauge have anything to do with it losing suction or is the gauge just for my purposes.

 

[wireform]

It's a sign new gauge is need but a loss of suction would have nothing to do with it.

 

[Teerump]

I’ll grab a new gauge. Would it lose suction if the pressure is just getting too high? Like from vacuuming up a lot of debris?