Hi,
I'll give you an update about the reported problem: it has been fixed in one of the previous X-Plane updates so the pointer now works correctly in the use of the program.
However, there remained a substantial similar problem in the X-Plane update menu, so the mouse pointer turns into a square and moves not continuously but with clicks.
The problem is particularly annoying when a mask appears that asks whether or not to overwrite the existing file, so it is almost impossible to choose between the options that require the choice between buttons to press.
Mac OS Mojave 10.14 (18A365a)
X-Plane 11.25r2