Unable to update PCEP session config

The PCEP module failed to reload after pcep session config is updated.

Reproduce steps:

Put to URL:

http://controller-ip:restconf-port/restconf/config/pcep-app-config:pcep-session-config

Body:

{
"pcep-session-config" :
{ "keep-alive-timer-value" : 30, "dead-timer-value": 120 }
}

Somehow the PCEP module failed to restart without a clear reason.

Karaf log attached.

Tested with Nitrogen and observed this. Issue was not observed in Carbon and Oxygen.