I have a 2015, 32' Coachmen Leprechaun Class C RV, on a 2015, E450 platform, now with about 26k miles on it..

I have had an ongoing issue relating to the 9U5Z-9F945-C, Fuel Vapor cannister. This part # fits my vehicle's VIN, btw. This issue primarily causes a check engine light error, as well as the usual gas cap off, etc. errors. More specifically, after hours skitching around under the 8 ton RV, I noticed this highlighted part (white plastic elbow) had only a nub of it's hose remaining connected, via a rubber hose. This can be seen in my hand. Based on extensive research, this plastic white elbow is part #9E629, as illustrated on an exploded diagram I found. Our local Ford parts guy came up with this coil of plastic hose, incidentally, with the same rubber hose on the bottom end of it, just like what I'm holding in my hand. So this must be what used to be connected? Problem is, that after extensive searching, I could not find the majority of the remaining original hose anywhere underneath the RV. The parts guy thought that because the coiled part is called fuel vapor line, that it must be connected to the gas tank. Unfortunately, I could not get myself in a position from under the RV to view where it could have been connected. Parts guy thought it might be the top of the gas tank, which is concealed to me. Does anyone know where this coiled hose connects? I'm pretty confident the bottom end, shown in photo, with rubber hose connection, connects to the white plastic elbow. Can anyone tell me where the other end connects? If so, do you have a readable diagram of photo of that connection?