App Engine not mapping custom domains

[Ayokunle Adesanya]

I setup custom domains on app engine a few month ago and it works fine. However, checked again today and it doesnt work. Althought the normal default url supplied by app engine works, the custom domain does not work.

[David (Cloud Platform Support)]

I would recommend re-mapping the custom domain. If after doing this, you are still not able to get it working, you should probably reach out to GCP support  as they would be able to inspect your project and work with you to find out what could be causing the issue.