DE not coming out during backwash

[brianbo]

Hi,
I have a 24' agp, Hayward Pro Grid DE 2420 filter with MPV = Hayward S710XR50.
When I opened the pool in June, I backwashed and no dirty water came out. A few weeks later I vacuumed and backwashed and no DE came out. Last week, I replaced the spider gasket that I bought at Leslie's and it is not a Hayward gasket.
First time after replacing gasket, I noticed a little bit of water coming out of waste so I went back and did it again. I did see some of the old gasket still in the grooves. I took it out and put the gasket back in. The grooves seemed clear of old gasket.

Now when the filter is running, a real lot of water comes out of the waste port so much that I had to connect a hose from waste that goes into the pool when the filter is running or water will go below the skimmer.
Als, when I put the MPV in backwash, the handle is sort of limp and no DE comes out but it has not come out the whole season.
1) Should I put glue on the spider gasket?
I did push it down as tight as I could.
2) Can the issue be the MPV and the filter or just the MPV?

I have had the filter and MPV for the last 8 years or so and no issues.

Either this is my last week or next week, I will be closing the pool. At that time, I will see if there are any tears in the DE filter.
Is there anything else that I should look at in the DE filter when I have it opened?

Any help would be appreciated.