If you are on P3D V4 you could try an exclude of PACZ in the elevation correction tool of ORBX Vector.
If you do not use V4 or you do not use ORBX it may be an inconsistence of scenery of a specific version (e.g. P3D V5) and an older Free-or Payware at that area. For instance there are a lot of such artefacts in V5 when ORBX V4 freeware airports are used.
So, I would step by step uninstall/install Free- and /or Payware that covers this area (Mesh, Vector, Scenery, Airport).
Karl