Ok sounds like the problem is at Prince George (CYXS).
1. Firstly just to get Plan G out of the way: Under data, make sure you run/Build Navigation Database. And following select the correct Display data for your sim (which is either FSX or P3D).
Prince George (CYXS) is a LARGE Airport, so in Plan G, under the Map tab the "Large" tick box that is on the extreme upper left must be ticked to see the airport icon for CYXS.
(Now if you tick "Large" it should appear.. if not, then there maybe something wrong with the sim/default scenery somewhere).
2. As for scenery abnormalities. Don't think RTMM has anything to do with Prince George (CYXS) persay but sounds like sometype of elevation issue. (ORBX NRM contains CYXS).
a. To find a scenery problem, first turn off any 3rd party mesh - to get back to default elevations/terrain.
b. If you use Vector - look in Airport Elevation Corrections and adjust CYXS (Enable or Disable)
c. Search for any .bgl scenery files that could be interfering at the location.
In this case Prince George (CYXS).
a) Do do a search for CYXS on your computer and see what it yields.
c) Do do a search for PRINCE on your computer and see what it yields.
d) Do do a search for GEORGE on your computer and see what it yields.
(If the search yields any of these bgl files that are for Prince George (CYXS) add OFF to those files (to turn them off). and try your sim locaton again to see if the issue is corrected.
Might be a bit labour intensive but really is the only way to find which bgl file is messing up the location.
Norm