This issue can occur if the ephone-hunt command is configured with hops that are more than what is specified in the max-redirect command.
The redirect from one ephone-dn to the next in the list is also known as a hop. The maximum number of redirects can be configured globally with the max-redirect command and can be configured for specific peer or longest-idle hunt groups with the hops command. If the maximum number of redirects or hops is reached, the call is dropped. The voice hunt groups are subject to a maximum redirect restriction.
In order to fix the problem, increase the max-redirect to the desired value.