Need some assistance or input on this issue:The client from PSTN successfully connects and talks with agent, but when the call is placed on hold, the client does not hear MoHCall flow>PSTN>GW>CUSP>CUCM1>Route Point>SIP TRUNK>CUCM2 (MTP PROXY)> Route ...

 I am receiving this error: WARN [1776] ConnectionManagers.ConnectionManager [ucm_1 [Cisco Call Manager]:Instance 1 Default <hostname of CUCM>] Monitoring Test Failed. [The remote server returned an error: (599).]

Cisco Unified Contact Center Management Portal 12.6ES10Render gadget failure: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.