Jim, My 2017 RLTS 27.5 was doing the same thing. I just brought it to the dealer for repair. (first time using that extended warranty). They Found that the slide out had folded over due to slide mis-alignment from the factory. Tore up the seal. They ordered a replacement. This was on the refrigerator slide. The other slide also was making a "popping" noise. They found that the slide needed to be synced, I thought for sure the non-metallic (Nylon) gear was chipped. They assured me that was not the case.
2017 Jayco 27.5 RLTS
2016 Ford F-350 crew cab Lariat. 6.2 liter