Thanks for your help.
The correct answer is here:
Desktop Icon Spacing
https://www.addictivetips.com/windows-tips/increase-or-decrease-desktop-icon-spacing-windows-10/
Open the run box with the Win + R keyboard shortcut. In the run box, type regedit to open the Windows Registry.
Go to the following location in the Windows Registry.
HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics

With the grid, you need to change the difference between the rows of the grid, and the columns. That means there are two values you have to edit. Each value manages a different aspect of the grid. The IconSpacing value will change spacing between columns, and IconVerticalSpacing will change spaces between rows.
5/2020 – mine was screwed up to too small -480. So changed both to -1234:
