That is indeed strange - is this happening when you start cold and dark and first power on the Garmin, or did you already changed something (switched to other modes)?
After power up I am 100% certain, there is a little plane, at least for the G3000, I am using. But I think this is also true for G1000.
Anyway I dind’t find a map symbol corresponding the white circle in the G1000 manual.