Layout dimensioning weirdness

[Buckyman]

I am pulling my hair out with this one
If I dimension the lower edge I get one value, if I dimension the upper edge I get a different value,
and both of these values is wildly incorrect as you can see from the SU screen shot
Dimension settings is auto

[Dave R]

It may be the modified scene causing the issue. It's normally not a good idea to modify scenes in LayOut. Can you share the LayOut file so we can see what you've got?

[Buckyman]

Here is the file, thx

[Buckyman]

I reset the scene which did not help.
I did some dimensioning in SU and determined that Layout is reporting the diagonal distance!