Phonebook not showing on Cisco IP Phone 7821

I’m having some more trouble with this device. I wanted to use phonebook button to display a list of my contacts. Apparently this phone needs to get this list from a server, so I started Apache HTTP and placed a sample directory.xml file on it:

<CiscoIPPhoneDirectory>
  <Title>IP Telephony Directory</Title>
  <Prompt>People reachable via VoIP</Prompt>
  <DirectoryEntry>
    <Name>Bob</Name>
    <Telephone>1234</Telephone>
  </DirectoryEntry>
</CiscoIPPhoneDirectory>

In phone’s config file I added this line:

<directoryURL>http://192.168.1.2/directory.xml</directoryURL>

When I press phonebook button on the device I can see from Apache log that it tries to grab a file (code 200 should mean success, right?)

192.168.1.4 - - [20/Jan/2025:17:30:34 +0100] "GET /directory.xml?locale=SIP_English_United_States&name=SEP700B4F903F00 HTTP/1.1" 200 232

but it only displays blank page with “Contacts (0 elem.)” header. I can see directory.xml from a browser just fine. Why isn’t this working?

For testing I tried to place this same file on my TFTP server used for provisioning, again logs show the phone grabbing a file but it displays nothing. I’ve read this phone does not support SMB so trying it didn’t work at all.

Is just a content of a file incorrect or should I “feed” it to the phone differently? Maybe there is a different, simple method to achieve a working phonebook? Maybe store it locally on the device? I need only like 5 entries in it. For now my placeholder solution is to map single digits to phone numbers of my choosing using dialplan.xml, but it obviously requires you to remember which is which and has no labels, not very elegant.

Thank you for any possible suggestions.