Bio pellets up and running, have ?'s

SMR1 Reactor
MAG 3 pump
Vertex bio pellets

2 questions:

I soaked pellets well over 24 hours like suggested, I used only a quarter of my 500ml bag also suggested, with that being said

I have pellets getting around the screens somehow and shot into sump

and most of the pellets are tumbling nicely on the bottom of reactor but many are clumped together at the top of the reactor. payed a lot of coin for this setup I hope it works correctly.

Are these observations normal??

 

New pellets will clump at first. The pellets should not be able to get around the screen. Is it set up properly? Maybe something is just barely out of whack.