Slur from grace note to principal note not joining properly.

When I try to connect a grace note to its principal note with a slur, the slur often does not end at the noteheads of the two notes concerned. In the past, I did not encounter this problem so much but I keep facing it now and it is super annoying as I have to manually reposition each slur. Furthermore, sometimes when I re-open the score after saving, the position gets automatically reset again.
See the attachment to have a better understanding of what I mean