Hi @S A
According to your description, do you mean when selecting the primary mailbox, Outlook doesn't show Quota Information in Status Bar?
If this describes your situation, could you have a check to see if you are choosing a folder rather than the root mailbox when viewing the quota information? As based on my test, for the primary mailbox, the quota information only shows when a folder is selected:
Besides, as regards to the "Quota Information" setting, please check if it's the same as the screenshot below:
In case the issue remains, it's suggested to run the command below for one of the affected users, then share the output here for further analysis after removing any personal information involved:
Get-Mailbox <identity> | fl IssueWarningQuota,ProhibitSendQuota,ProhibitSendReceiveQuota,UseDatabaseQuotaDefaults,database
Get-MailboxDatabase <db name>|fl IssueWarningQuota,ProhibitSendQuota,ProhibitSendReceiveQuota
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