Water leak only when traveling

[Mikelff]

Hi all,
I am trying to find where water is coming in from the rear of my living room slide. Only leaks when traveling in the rain. No leaks while camping in heavy pouring down rain. Cannot find evidence of any moisture in the ceiling, walls or anywhere else when stationary. Just had my roof inspected and re-sealed two weeks ago. It appears to be coming in from the wheel wells somewhere. Soaks just the edge of the carpet at the rear of the big slide and sometimes runs along the bunk room carpet edge but doesn't seem to be coming from that side. Dries after an hour or two. Would appreciate any ideas where to look, and where this water might be getting in. Driving me nuts. Anyone else have this problem? To save you time, my rig is a 2018, 358 BH High Country. Thanks for your help!