I thought I should point this out. This is the what are you doing for Praea Euq VP-M c21-1
Those 2 signals are both Class III gas giants, but they're pretty far apart. The lower signal is a normal CIII and the higher one was the GGG. I also noticed the same thing in Squern AF-N c21-0 but I don't have a screenshot and I don't remember if it was higher or lower, but there could be a way to identify GGG's from the FSS.
No, sorry, but I'm pretty sure the difference between those two signals is that one of them (the GGG) is ringed, the other (planet 2) is not.