Rally Points not placed where instructed, cannot be moved/ corrected manually anymore

#### Issue details
When placing Rally Points, they don't end up where intended.

When adding a Rally point, I right-click at the desired point and add a Rally Point.
After it is created however, the point is not where the cursor was pointing on the screen at the time the right-click occurred.

It is in the general vicinity, within about 1-2 meters, but seems to end up at a regular offset at about 5 o'clock from the point clicked.

Additionally, they cannot be "grabbed" and moved anymore, as used to be the case.
Instead, all have to be cleared and the setting of all Rally Points has to be repeated, if one is off.

Would be great if this could be fixed again. Thanks!

#### Version
1.3.73 build 1.3.7535.17741

Reproduce Rally Point placement and editing in Mission Planner using the reported 1.3.73 build, checking the screen position against the created point. Trace the Rally Point map interaction from right-click creation through selection and dragging. Done means points appear at the clicked location and can be moved or corrected individually without clearing all points.

Written by the indexing model from the issue text.