First taxiway point offset large amount

Version: SU16 - 1.39.9

Frequency: Consistently

Severity: Low

Context: Editing taxiways

**Bug description:When adding a taxiway with “one-click”, the first point is not added under the mouse pointer, but way off screen to the left. All subsequent points are correctly placed, until I end one-click. But the same thing happens the next time I switch it on. First point has to be manually dragged to the correct place

**Repro steps:*Edit airport, in object list select Taxiway Point, and one-click. Click anywhere to start adding taxiway, first point will be as described.

Same thing happens if I select an existing taxiway point and repeat the above to extend it.*