We were preparing to go camping in our 2018 320s Outback a few weeks ago and noticed 2 problems. First, the freshwater and grey water readings on the See Level II gage were "Opn". Then, before the freshwater tank filled, I noticed water dripping down from underneath. I took the trailer to the nearest RV repair shop (2 hours away). The repair person showed me what he found: a pile of branches and debris (classic "rat's nest"), chewed-through tank-sensor wires (causing the "Opn" readings), and a chewed-through vent pipe (causing the freshwater tank to leak into the underbelly. The shop cat went into the underbelly and caught the pack rat. Fortunately, the T@B was sealed well, and the pack rat was confined to the underbelly. I'm now working on rodent-proofing the underbelly.