Description:
If you make cell formatting only changes (no cell contents) in a column, from column 65 and up, they do not get saved.  The cell formatting only appears to save if somewhere in that column there is a cell with cell contents (doesn't have to be the same cell as the formatting).

Example: I was using calc to draw floor plan layouts using cells as increments of area.  No cells had contents, but was setting background colors.  When saved, everything in first 64 columns saved, nothing 65+.  If I change a cell background in column 65 (Column BM by default naming) and in that same column change a different cell's column to have a value in it, then it saves.  If you then remove just the content from the one cell, leaving the background of the other cell, when you save, the entire column is wiped out.

Steps to Reproduce:
1. New File
2. Go to Column "BL" (64th column)
3. Change a cell background color
4. Go to Column "BM" (65th column)
5. Change a cell background color
6. Save file and close
7. Reopen file (BL color change still there, BM color change erased)
8. Change a cell background color in column BM
9. Put text (single character will do) in a different cell in column BM
10. Save and close
11. Reopen file, both text and color cell show in column BM
12. Delete text from BM cell with text, but leave colored cell
13. Save and close
14. Reopen file, colored cell is gone.

Actual Results:
Cell formatting in columns 65+ are removed if column has no cell data in any cell.

Expected Results:
Formatting in all cells regardless of where in spreadsheet, and regardless of other content in column, should be saved as edited.


Reproducible: Always


User Profile Reset: Yes


OpenGL enabled: Yes

Additional Info:
Output from OpenGL command 
OpenGL vendor string: nouveau
OpenGL renderer string: NV137
OpenGL core profile version string: 4.3 (Core Profile) Mesa 20.0.4
OpenGL core profile shading language version string: 4.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 4.3 (Compatibility Profile) Mesa 20.0.4
OpenGL shading language version string: 4.30
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile
OpenGL extensions:
OpenGL ES profile version string: OpenGL ES 3.2 Mesa 20.0.4
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20
OpenGL ES profile extensions: