Bug: shorten a tied note with shft-alt-arrow

I have import an Music XML. There is a eight note at the end of an bar tied to a half note in the next bar.
Shorten this note with Shft-Alt-Arrow < give a strange (!) value on the last beat of the previous measure.
Lengten this note first with Shft-Alt-Arrow > and after that shorten will work perfect.

See GIF (I have press UNDO before lengthen the note)
ChangingLenght.gif

Notes imported from MusicXML files have all sorts of funny properties set on them, in order to try to maintain the original notated appearance of the notes in the source application. To remove said properties, use Edit > Reset Appearance.