It would be helpful to know the model year. If you add it to your signature line, it will help us help you, now and for future posts.
Crossroads has used Frigidaire residential refrigerators for a few years, and a general instruction sheet to replace the ice maker filter states the shut off is in the grille under the fridge.
I also found two years, 2018 and 2019 that say the shut off to drain the fridge water line is under the kitchen sink, and is part of the low point drain. Maybe look under your RV for the low point drain, and locate where it might come up through the RV.
Doug and Patience and Shelby the mutt
2015 Crossroads Sunset Trail Reserve ST26RB
2013 Ford F-150 3.5 EcoBoost XLT Supercab 4x4