But it is being reported to the manufacturer's so it's not something
coming out of the blue kind of thing.

I dunno. The Lexus system doesn't make a real big deal out of a lost signal
right away because it has the ability to project an estimated fix from speed
and direction telemetry from the car, but both my Garmins (truck/boat) start
squawking right away if a signal/fix is lost. I don't see any posts about
anomalies over at sci.geo.satellite-nav, and if anybody would be on top of
this sort of thing, it's those guys. Try posting your observations over
there, and see what sort of responses come up. It seems I remember that a
new GPS bird was just launched a couple of weeks ago. Maybe what you're
experiencing is related to bringing the new bird online?