This behavior is usually caused by a cache plugin. Configure your plugin, for example you can disable cache for logged-in administrator, or add plugin folder into exception. Or just do not forget to clear the cache after each saving of the preset settings
Cache > Exclude Select "Administrator" role for exlcude
DIVI > Theme Options > Builder > Advancedand enable the toggle Static CSS File Generation
WP Super Cache
Check the box beside "Disable caching for logged in visitors" option in Avanced settings
WP Fastest Cache Settings
In plugin setting check the box beside "Don't show the cached version for logged-in users"