Seneca v Map Range

[Will273 23]

When I'm at KORD Chicago or KCLE Cleveland and fly in the area the map scales out to 50 miles but only a small part of the lake shows in the map and the rest is green where it should be blue. So far it only seems to happen around these lakes and wondered if anyone else notice that. Just trying to find out if it's a glitch in the aircraft or my computer settings. Thanks.