I'm very sorry to hear about the issue!
May I ask you in what version of Archicad are you noticing this problem?
In Archicad 25 and 26 I don't happen to see this error.
Please correct my steps if you did it differently:
1. I placed a wall with insulation
2. I placed a grid using the grid tool
3. I placed three dimension points: two for both sides of the insulation and one for the grid (similar as you showed on the picture)
4. I saved this file as a module file
5. I opened a new Archicad instance and loaded the module file (first time I loaded all stories, second time only the story which had my wall in it)
6. I was able to see the dimensions both times
Are you able to create a new file and reproduce the issue?
If yes, could you please provide me the steps?
Technical Support Engineer