There is a huge gap between the grace note and the ‘main note’ if you use a new tempo indication at the place where you use a grace note.
The only workaround for this is to move everything manually.
You should find everything is correctly positioned if you input the tempo mark at the position of the main note, not the grace note.
Of course I tried that Lillie - with the same result - really !
Damn - now it worked…I swear that I entered the tempo at the main-note and it didn’t work…grrrrrrr… 