I'm pretty sure it's to do losing network connectivity.
1. Restart Zoiper: LDAP search works.
2: Turn off WiFi. Zoiper says that it has detected a network change, applying configuration changes.
3. Try an LDAP search whilst there's no network: No results
4. Turn WiFi back on Zoiper says that it has detected a network change, applying configuration changes.
5. Try another LDAP search.
Expected outcome: The network changes applied when Zoiper detects a new network allow LDAP searches again.
Actual Outcome: No LDAP search is executed, no results show.
Can you reproduce the problem with these steps?