Got it. Mine is a 2017 Four Winds 24F - basically the same coach.
I do not have any bag in my slide, instead there is a 4Ē wiper seal on the bottom of the slide opening on the outside. It is a piece of junk that is suppose to seal the slide from the outdoors. I use a cut pool noodle instead and install it in the slide floor when extended. I believe the bag in yours it to provide the seal.
As far as 120VAC, I have two rubber jacket cables that come up in the slide and they terminate in a junction box. One cable is connected to the water heater and the other to the receptacles in the slide. This is the rats nest I have under my rear bench seat. It appears they used molex connectors vs junction box for your AC.