Hi and Welcome to The Forum!

Please take a look at THIS post for some info on DE filters.

There is a good chance that your 'tube sheets' are cracked . (the tube sheets are the plastic disks that hold your filtering 'fingers')

I'd suggest that you open up the filter and check the sheets, DE will only enter the pool through a broken piece of the filter's internals - this includes missing/ bad seals.

If you need any help with this, I can almost do it with my eyes closed and will 'walk' you through the process.