During the time , between the lights working and changing the bulb and them not working , did you move the slide in or out?
May be a problem with the 12v supply to the slide, usually a coiled wire below the slide that follows the slide as it extends. You will need to check for power at both ends of that wiring with a multi-meter.
Lights in the slide are 12v, outlets are 110 so are supplied by different wiring.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.