Try this
right click start button
choose powershell (admin)
type
SFC /scannow and press enter
once its completed, copy/paste this command into same window:
Repair-WindowsImage -Online -RestoreHealth
and press enter
SFC fixes system files, second command cleans image files, re run SFC if it failed to fix all files and restart PC
I hate how Google thinks it knows what I want and shows opposite results... Taskbar icons, oh you want to decrease spacing... even though I typed increase.
possibly a tablet setting -
https://www.thewindowsclub.com/taskbar-icon-spacing-is-too-wide-in-windows-10-or-surface-pro-device although that relates to touch.
I know screensize can reduce number of shown icons but not the spacing...