config file doesn't load my 'Styles' shortcut keys

I’ve created shortcut keys for paragraph styles.
I’ve saved them successfully in a .cfg file having gone through the Customise menu.
But when I reload, the shortcut keys don’t work.
When I checked the Customise menu, I got this in the shortcut key description:
.uno:styleapply?style:String=ScriptSlug&familyname;string

It appears to be text from the config file but not the shortcut key.
Any thoughts on what’s going wrong?