Dear friend!
You can troubleshoot the problem in the following ways:
1. Check whether the client-side equipment at both ends supports channelized services. If the service is un-channelized, configure it as a VC-4 service.
2. Check whether the J0, J1, and C2 byte configurations of the interconnected ports are consistent.
3. Check the fiber patch cords at the site and ensure that the fiber patch cords are correctly connected.
Thanks!