Hi Paul,
Thank you for contacting Syncfusion support.
We have checked the provided WMTS URL with the UrlTemplate property of the Maps component. We are unable to render the tile map with the provided URL. We suspect that you have replaced the domain name in the URL. Can you please provide the hosted link for the tiling service(WMTS) to reproduce the reported issue? It will be helpful for us to analyze further and assist you better.
Regards,
Swetha Babu