This happened on our old '03 Kiwi 17a after about 5 years. One clip, then the other clip. A replacement vent was about $6, plus the butyl putty. 30 minutes to change it, most of that time spent cleaning the old putty off.
2013 Jayco Jayfeather X20 E, 2008 GMC Sierra 1500 Crew Cab Z71 SLE