When using points as the measurement unit, setting the grid subdivisions per unit size does not appear to persist, and is reset on restart of libreoffice (all applications: draw, impress, writer, etc).
Steps to Reproduce:
0. I'm able to reproduce on a (relatively) new, clean install of Fedora 27; I have not attempted to reproduce in a pristine VM. This issue does not appear to effect all measurement types, such as millimeters/centimeters, but I did not exhaustively test all measurement types.
1. Select "points" in the Tools menu >> options... >> LibreOffice Impress/Draw" >> General >> Unit of measurement; save via "OK" button.
2. Modify the grid size and subdivisions in the Tools menu >> options... >> LibreOffice Impress/Draw" >> Gird >> Resolution/Subdivision ; enter 72.0 for all values here; save via "OK" button.
3. Restart libreoffice.
4. Inspect the grid size and subdivisions in the Tools menu >> options... >> LibreOffice Impress/Draw" >> Gird >> Resolution/Subdivision.
The grid resolution is typically preserved and for saved value of 72.0 pt, after restart the grid resolution is still 72.0 pt. However, for a saved value of 72 (spaces) grid subdivisions, after restart a value of 74 spaces will be presented . The new grid size will result in incorrectly positioned elements when snapping to grid points, other objects, etc.
The grid subdivision option should be correctly preserved.
User Profile Reset: Yes
User-Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.101 Safari/537.36
Arch Linux 64-bit
Build ID: 14184060bd2249a492ea44d36463914c421e6ce5
CPU threads: 8; OS: Linux 4.16; UI render: default; VCL: kde4;
Locale: fi-FI (fi_FI.UTF-8); Calc: group
Built on April 23rd 2018
Verified as still present in Version: 184.108.40.206, Build ID: 220.127.116.11-3.fc29