I saw that it was a month old pool. Any chance that there has been usage from people over applying suntan lotion or baby oils? Cartridge filter elements can quickly accumulate oils in the element, which will clog and cause high pressures quickly. Normal cleanings will not remove the oils. What's worse is that if you try to clean it by using a mild acid solution, it will lock in into the element pleats and make it worse. Tri-Sodium Phosphates (TSP) is typically what is used to soak the elements to degrease it, before using any acid solution to clean it.
Older elements can also clog up quickly, as the pours clog and do not get as clean as time goes on. I know this is not your situation, but it is another reason for elements to increase in pressure and get dirty quickly.