OTD marks one of the origin servers as offline/unreachable when origin servers are using a different set of Certificates.
It can work only with a single origin server at a time.
Add the following inside element in server.xml for origin server pool:
Path:
/u01/data/otd-instance/otd_domain/config/fmwconfig/components/OTD/instances/otd_opc-config_xxxxxx/config
<context-pool-size>0</context-pool-size>
