By default Warp is configured to wait two rings and then wait one second before answering any call. Waiting two rings is done for a reason.
Typically, caller ID on lines is send through modem signals between the first and second ring. It can however be shorten by Pika. To do so, in the file '/etc/pika/pikagp_aoh.cfg' add the following line:

...
[TRUNK_2XXXXXXX]
interface=board...
...
...
disconnect-lcterm|tones
ringcount=0 ; <== add this line
...

This change requires a restart of Asterisk. Also, adding this line will force Pika to answer trunks after only the first ring is detected. The consequence of this is that you may never get caller ID.