This is a day one bug of the flightplanner and it affects all planes. Quite a few threads on this also often known as the “turnaround bug”.
Currently Working Title is working on the G1000NXi, which will be the prototype for the replacement for the buggy Asobo flightplanner.
In addition, FBW has already made also excellent progress of writing their own new flightplanner, which you can test in their experimental version of the A32NX (Pc only). That flightplanner does not exhibit those bugs you are experiencing, among many other goodies.