It appears that you are experiencing an issue where the Developer Portal for your Azure API Management instance on the Standard v2 tier is still displaying the default *.azure-api.net URL instead of your configured custom domain. This can indeed lead to confusion for developers who may inadvertently use the wrong base URL for integration.
From the context provided, it seems that the issue you are facing is a known bug related to custom domains in the Standard v2 tier. Unfortunately, the specific details regarding the ETA for a fix rollout in your region are not available in the context provided. It is advisable to keep an eye on updates from Microsoft regarding this issue or to reach out to Azure support for more specific timelines.
In the meantime, ensure that all configurations are correct and consider informing your developers about the current situation to mitigate any potential integration issues until the problem is resolved.