Users forbidden from viewing service dialog associated with button

I’ve created a button and assigned it a service dialog. When a user views their VM, they are able to see and click on the button but the service dialog does not appear and instead a loading symbol is shown indefinitely.

Debugging this in Firefox I can see the user is getting a 403 Forbidden error when attempting to load the service dialog.

The user is using a self-service role copied from the default one and if I grant them the Automation/Automate/Customization permission they are then able to view the service dialog, but also edit all other service dialogs.

The user/group does have a tag assigned to them but I don’t believe service dialogs can be tagged? Access restriction value for the role has also been switched to none, as shown in the above image.

Any help would be appreciated, I’m guessing I’ve just made a mistake in the configuration somewhere and I’m just unable to see it.