Hi @Andrew Ramshaw , For WCF, unfortunately the configSource attribute does not work on the <system.serviceModel> section group, but you can still apply it on the child config sections. For more information about it, you can refer to this link:
https://weblogs.asp.net/cibrax/configsource-attribute-on-system-servicemodel-section
If the answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Best regards,
Peng Ding