Yes, the extra noise issue concerns me. It may be just a co-incidence that the two weakest stations dropped happen to be VHF.
But I have been in touch with Wingard Technical support. Yesterday they said it sounds like a problem with the VHF side of the SensarPro.
They are sending me a replacement.
Unfortunately, I will not be at this location when I get it so will lose my best "control" variables. But I will be watching for any similar issues with the replacement anyway. I will be back at this campground next month (not on the same site though and even a few feet difference can affect this stuff) so that will be another good check.
Thanks again for everyone's input!