AC was cooling fine. Now, won't cool room even though cool air comes out. Exhaust hose is extremely hot.

Based on the product specifications available online, the Noma 043-6131-0 portable air conditioner does not appear to have a heating mode or a heat pump function. It is designed only for cooling and dehumidifying a room.
If you are seeing a heating mode on the unit, it may be a different model or a mislabeled function. In any case, it is always recommended to follow the manufacturer's instructions regarding the use of the exhaust hose. The exhaust hose is necessary for venting the hot air generated by the air conditioning process out of the room, regardless of whether the unit has a heating function or not. Running the unit without the exhaust hose can cause it to work less efficiently and may also create a buildup of heat and humidity in the room.

U need that hose to direct the warm air outside the area to be cooled. If you remove it, the hot exhaust will stay in the room being cooled and negate the cold air being directed into the room.

That is why regular room AC units are mounted on window sill. Cold air in, hot air out.

No you should not because it is counterproductive. You can always purchase a new exhaust hose at your local hardware store!!!

Air conditioners generally cool the air 15 to 20 degrees. 80 degrees in return should be 65 in supply. 70 degrees in return should be 55 in supply. If the a.c. is in that range it is working fine and doing all it is going to do.

If you need further help, reach me via phone at https://www.6ya.com/expert/thomas_092728000e6acb79

The fan that blows the air blows through the heater coils before it blows through the A/C.As long as the heater doesn't come on, there is not much that can be done. ZCooking the attic room will be a problem because it is the heat rises thing, and on top(literally) of it all, the roof is radiating heat.

The manufacturer suggests, even though state not required, to leave
required ac termination kit in place even in dehumification mode.
This should reduce your energy conflict.

Clean you filter and clean the area under the intake duck it will solve your problem

The Pinguino's exhaust pipe has to be attached to the window bracket to direct the air hot air out of the room, otherwise the room can't cool properly.
The owner's manual has several troubleshooting remedies for you to try:
1)  If the window is open, close the window. 2)  If there is a heat source in the room (burner, lamp, etc.), eliminate the heat source. 3)  If the exhaust hose is detached, connect the exhaust hose.  (My recommendation is to connect the exhaust hose to the window bracket and direct the air outside.) 4)  If the air filters are clogged, clean or replace the filters.
Remedies that aren't mentioned in the manual, but you might find helpful:
1)  Make sure that there are no kinks in the hose, and that the hose either remains straight or has a gentle curve when directing it into the window bracket.
2)  A sunny window reduces the maximum power and efficiency of the unit.  Placing it in a sunny window reduces your BTUs by at least 600, which means the maximum square footage of cooled space is reduced.  Cooling a kitchen requires at least 4,000 BTUs alone, which is nearly half of the unit's BTUs.  Try to place the unit by a window that receives minimum to no direct sunlight.
Finally, stating the obvious, if the room isn't cooling, the room is too large for the unit.  The PACL90 cools up to 400sqft.  Bear in mind that the air from these portable air conditioners cannot move around corners very well, so try to set it by a window in the central part of the room.

Some units do cool/dehumidify only im afraid why cant you let the unit dump its hot air into the room then it wont heat or cool the room?