Hello all
I found the answer myself - by accident.
If all your Tenant Payloads are not displaying, check the status.
In my case it was because the payload status was 'draft'.
To overcome the issue, I clicked on the 3 dots (vertical ellipsis) and clicked on 'Copy Payload'. This brought the wizard up. I went through to completion.
When I checked the status, a new version of the template said the status was 'Ready', however the old draft one remained.
Again I clicked on the vertical ellipsis and selected 'Archive', which then removed the entry from the list.
I applied this 'fix' to both of the templates and now all my templates are displayed