DIAGNOSIS It's acting more like a fan than an AC. The most likely culprit is the exhaust setup. If the hot air isn't venting outside properly, it just gets recirculated and the unit can't cool.
FIX Double-check the entire exhaust path. The hose must be fully extended (all segments clicked) and connected tightly at BOTH ends—to the back of the unit and to the window bracket. The window kit must be installed so the hot air vent is completely outside, with the adjustable panel filling the window gap. Use all the foam pieces to seal it. Then close the window snugly on the bracket.
IF THAT DIDN'T WORK Make sure you're not trying to cool too large an area. This is a 10,000 BTU unit meant for small rooms (~250 sq ft). Also, check that the air filter (behind the front grille) is clean. A clogged filter severely reduces airflow and cooling.
HEADS UP Portable ACs are inherently less efficient than window units. You'll get the best cooling if you keep the unit close to the window (to minimize hose length) and keep the room sealed. Don't expect it to cool a sun-drenched, open-concept space.