daknetworks.com

Offline Address Book (OAB) is found with the following:
Get-OfflineAddressBook |fl

To get the needed info:
Get-OfflineAddressBook |select name,GUID,GeneratingMailbox,VirtualDirectories |fl
Get-OabVirtualDirectory |fl

OAB logs are here (default location):
C:\Program Files\Microsoft\Exchange Server\V15\Logging\OABGeneratorLog

OAB changes are kept here (default location):
OC:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\OAB\{guid-from-get-offlineaddressbook}

The files inside have a randomly generated GUID2. The manifest is the xml file.

Force an update of OAB:
Get-OfflineAddressBook |update-OfflineAddressBook

The OAB locally is found here:
%LOCALAPPDATA%\Microsoft\Outlook\<GUID2>

The GUID2 matches the GUID2 found on the server.

Please see the following for a deep-dive fix:
http://www.daknetworks.com/blog/584-oab-0x8004010f-hafnium-fix-outlook-address-book-deep-dive-fix

NOTES:
https://techcommunity.microsoft.com/t5/exchange-team-blog/the-case-of-constant-oab-generation-and-full-oab-downloads/ba-p/1031610
https://msexchangeguru.com/2013/12/04/e2013-oab/
https://www.youtube.com/watch?v=AvywR9CWYHs#t=2246