Please consider the following scenario
A collector prn01.mydomain.com is used for a site. For a disaster recovery option another collector is installed - prn02.mydomain.com. A CName record is created with the name prn21.mydomain.com and points to prn01.mydomain.com. Now, we imitate the first collector's failure as if a disaster happened. The prn01 is shutdown, prn21.mydomain.com now points to prn02.mydomain.com.
When a user email@example.com enters his PIN code on a terminal the message "you have no documents" gets displayed as usual, but when another user firstname.lastname@example.org enters his PIN code on a terminal the message "you have no documents" appear only after about 30 seconds. The difference between those users is that the later has unreleased jobs on the failed collector.
AFAIU this happens because the prn02 attemtps to reach the prn01 for a list of jobs and waits kind of network timeouts until the prn01's response. If that is the case can those timeouts be controlled anyhow? This particular customer implemented a very short period of session on all of theirs terminals (just 15 second), so unless one's constantly touching a screen, MFDs return to the welcome page on its touchscreen and never display the "no documents" message