They do that when plumbed that way. Its a scavenging effect. As air is sucked past tge opening, it creates more vacuum at that spot.. ever notice how the stock filter finders are never in the intake tubing? They are always in the filter housing on a corner or backside so that the air sucking through has to suck it closed amd not scavenge it closed.. plug tge hole and throw it out..
For what it is worth, swamps uses the Donaldson version of the 6637 and has made over 800fwhp with it.. its the only filter they use also..
if you want more flow to ease your mind then stick a 2790 filter in there instead or go with dual 6637s.. i have done it in the past and works great.. zero pull on the minder that way too..
live life full throttle