Geometry grid has one line that loops back

[BCorson]

Hi, I have a Philips 65inch RPHDTV. When setting geom. and convergence, there is a line in the lower left corner that is in an "S" shape.(not quite as sharpe of a curve). The thing I can't figure out, is that it only appears when the RED is laid down on top of the GREEN. BLUE is not affected, neither is the GREEN. The line can be moved easily, but not straightened out. I believe my SERVICE MENU settings may need adjustment, but I don't know which ones to check.This set is only 4 years old, and all other functions work perfect. This is making me nuts... Somebody please help. Thank You in advance, Brad