Ran into a bug when testing on beta by editing the existing TemplateData for Infobox person in the TemplateData Editor:
* Suggested values field didn't show for parameters with the types for which it should be enabled, until I clicked on and re-selected the type or selected another type for which it is enabled. Only after I interacted with the "type" field would the suggested values field show below it.
* I also tested with adding new TemplateData and new parameters. They are set by default to type "Unknown", which should then show the suggested values field in the TemplateData Editor automatically, but I still had to do the same work around to get it to appear. (recorded screen to show this)
 If a parameter is set to one of the types where Suggested Values should be visible, this field visible in the TemplateData Editor without the user taking any action.