weak signal with full bars???

I had something unusual happen today. I was flying like normal near max altitude directly overhead and then realized S2 was in the wrong position (I usually keep it in the center) from storing it in my protective case. I got confused about the position of S1 and switched it out of GPS mode...

I've been battling trying to get longer Range with my P3S but I'm not starting this thread directly for that purpose (not looking for suggestions to extend Range)... My QUESTION is: Has anyone ever seen this before = Weak/Lost signal warning when the RC still shows FULL Bars or only down 1-Bar...