site mailbox timezone settings

Hello,

I have a sharepoint site with a lot of subsites with the mailbox app on it.

When users go to the mailbox the fist time they always get the timezone and language settings.

I tried to automate this and set these with powershell using following command as site admin:

Set-MailboxRegionalConfiguration -Identity xxxxx -Language 2067 -TimeZone "Romance Standard Time" -DateFormat "dd-MM-yy" -TimeFormat "HH:mm"

After this I check the sitemailbox with this command:

get-MailboxRegionalConfiguration -Identity xxxxxx

output:

RunspaceId                            : 48e46498-f3e1-4f0c-8d38-0b4592b393fb
DateFormat                            : dd-MM-yy
Language                              : nl-NL
DefaultFolderNameMatchingUserLanguage : False
TimeFormat                            : HH:mm
TimeZone                              : Romance Standard Time
Identity                              : xxxxxx
IsValid                               : True
ObjectState                           : New

Seems all good to me but the user still gets the request to select a time zone.

Anyone an idea whats going wrong?

thanks