System Settings keeps overwriting Sub-pixel Rendering with 'RGB'
STEPS TO REPRODUCE
1. Set sub-pixel rendering in Fonts with 'None'
2. Move to other Font Management and back to Fonts or reopen System Settings and go to Fonts
3. Sub-pixel rendering shows as 'RGB' instead of 'None'
Sub-pixel rendering can't be disabled from System Settings
Sub-pixel rendering shows None and Sub-pixel rendering become disabled
Operating System : Arch Linux
KDE Plasma Version: 5.17.4
KDE Frameworks Version: 5.65.0
Qt Version: 5.14.0
Ah, this is a side-effect of Bug 416140.
*** This bug has been marked as a duplicate of bug 416140 ***