normally I would expect the issue to be unrelated to the loaded aircraft...maybe only by coincidence due to overall msfs load or something.
In the end "it seems" to come down to the fact that GCLP, unlike the other airports using the vdgs driver so far, is quite "mesh volatile" due to its location, so the altitudes at which certain objects are placed in relation to ground elevation are sometimes not updated correctly. Have you tried what happens, if you take the showcase (drone) camera, move several 100m away and come back to your position? Sometimes this fixes the wrong altitude placement.
Nevertheless, we are going to look into implementing an alternative way which does not rely on having the correct ground elevation.