loss of suction in pool vacuum

[p-harm]

I am in my third year of using an Xstream filtration system and have not had any issues until now. First, air pressure is building up inside my filter housing to possibly dangerous levels after only a couple of hours of operation.

Second, when I hook the vacuum hose into the skimmer outlet leading to the filter I lose all pressure after about a minute and the vacuum will not work. I do not have any leaks or damage to any part of the motor or filter and have no clue why these things are happening.