Thank you for making that available.
It does have a problem and I had to End the krita appimage when I got tired of waiting for it to open.
The problem has something to do with the vector layer, possibly involving text in particular.
If I remove the vector layer aspects from inside the .kra file then I can open it and see you very impressive grid.
I can make a similar document and Save it to a .kra file then open that .kra file with no problems.
I tried to replace the vector content of your .kra file with that from my .kra file but the resulting .kra file would not open properly.
I’ve had a look around inside your TEST003.kra file and can’t fine anything that could stop it working but there must be something wrong, obviously.
Did you apply any transforms to the vector text after you’d made it?
Here is a screenshot of my working version of your document (no grid for me):
Here it is, can you open it:?
https://drive.google.com/file/d/1VQeRs27U-aFkG11HLsiJBW3vIJ-p0j71/view?usp=sharing
I tried to make it as similar to your TEST003 as I could:
The difference i that I used text flow wrapping inside the text box but you seem to have used line feeds in your text.
I tired removing the line feeds from the .kra file vector-text content but that didn’t fix the problem either.
Can you try this again but with simple text content that fits on the layer and not use any kind of transform operation on it?