Definitely sounds like a permission issue @Suresh Bettadapur .
The first thing to do is compare your access on that particular function app resource with those of your colleagues. You can do this by click on the "View my access" button under the "Access control (IAM)" blade. Another way to check your access is to run az functionapp function list --name <function_app_name> --resource-group <resource_group_name>
or use Web Apps - List Functions - REST API (Azure App Service) | Microsoft Learn. When it fails, you should receive a message with the role access you're missing.
Another possibility is the list of Functions has been moved (relocated) to the Overview blade as shown below.