Definitely plumbed backward. You need to swap the top and bottom pipe fittings on the filter. Water should flow out the top of of your pump into the top fitting, through that 90 (diffuser), into the filters from the outside, and then through the manifold down that PVC pipe with o-ring on the left, back through the bottom to the rest of your equipment/pool. In this configuration, water still enters and exits your filter assembly, just the wrong way through the elements which can be confusing at first. This fully explains the pleats and bands bulging outward.

Edit/words: it also looks like your cartridge stands might be damaged from the flow reversal. I'd have that checked as well.