HI
1."Custom Applications settings "
what's application settings did you set?
is it possible we can configure custom setttings for server build-in app ?
2.what's your rds environment?are all rdsh server in on-premise environment ?are they all pure Microsoft rds environment (none citrix rds environment) ?
3.are 4 rdsh(RDsession host) servers in the same collection ?
4.are office container and profile container in the same vhd location on different rdsh servers respectively?
are all rdsh servers' VHDLocations settings for office container are the same?
HKLM\SOFTWARE\Policies\FSLogix\ODFC
are all rdsh servers' VHDLocations settings for profile container are the same?
HKLM\SOFTWARE\FSLogix\Profiles
5.did you set "IncludeOutlook" value to 1 on all 4 rdsh servers ?
HKLM\SOFTWARE\Policies\FSLogix\ODFC
IncludeOutlook DWORD 1
1: Outlook data is redirected to the container.
0: Outlook data isn't redirected to the container.
Configure Office Container to redirect Microsoft Office user data
https://video2.skills-academy.com/en-us/fslogix/configure-office-container-tutorial
6.if the problem persist ,
first,we can try to set outlook settings for user1 on rdsh1 then logoff and logon rdsh1 again to check the outlook setting is correctly like picture.finally capture a fslogix logs on rdsh1.
second,logon rdsh2 by using the same user1 account and capture fslogix logs on rdsh2 then compare which difference between fslogix logs on rdsh1 and fslogix logs on rdsh2 for the same user1 account.
Using the FSLogix support tool to troubleshoot FSLogix Issues
https://social.microsoft.com/Forums/windows/en-US/0935e903-95d6-497a-9d9a-ae6ba5ece937/using-the-fslogix-support-tool-to-troubleshoot-fslogix-issues?forum=FSLogix