Phonebook Downloading

I'm having issues getting a phone to download a phonebook.xml file.

I am putting the phonebook.xml file in the following directory:
/var/www/fusionpbx/app/provision/pb/<mac address>/
I can see the phone asking for the file in the access.log of nginx, but it doesn't seem to be correct.
Code: - - [25/Mar/2020:11:18:31 -0600] "GET /app/provision/pb/01234567890ABCDE/phonebook.xml HTTP/1.1" 200 89 "-" "Grandstream Model HW GXP2135 SW DevId 01234567890ABCDE"
Note: Obfuscating the Mac Address and IP address.

If I put a simple text file in the directory , I can pull it up in a browser, which makes me think I have the correct path.

When I try to load the phonebook.xml file, I don't get the same one I have in the directory. If I upload the file directly into the phone from the phone web page, it works as expected.

Any help would be greatly appreciated.