Need more info - are you plugged in, are you dry camping, what type of system, is this isolated to the BR, etc etc. That said - how much charge is in your batteries? Low batts - depending on the system, will not have enough power to run the slide. Your overhead lights are also 12v and again, low battery will affect them. Try running the genset or plug into shore power.
If it's isolated to the BR and other slides/lights work, make sure you check all the fuses/breakers. We had an instance once on an older MH where a GFCI was tripped and I was surprised what else was on that circuit. Took forever to figure that one out.
2023 FR Sunseeker 2400B MBS