Retention policy not being applied (general weirdness)

So in my org we are fully O365/EXO, and my job this week was to setup retention tags and assign a policy to a support inbox. This inbox just forwards to Salesforce so nothings critical. so I setup two tags: 3 months to archive, and 6 month delete from archive.

I created a Retention Policy called Support Inbox, and applied it to the mailbox via ExchangeOnline web gui.

Now I have been out of the EXO game for a couple years but remembering on-prem I recall you could force that policy to be applied immediately by starting/restarting the Mailbox Agent. I think that's true to EXO as well.

So checking the available tags, all default tags were an option. I waited overnight after assigning the new Support Inbox policy and when I rechecked what's available in the mailbox itself now there were zero tags.

So yesterday I removed, and reapplied the Support policy then waited until his morning but the result is the same. The I have no tag's available.

So I'm sitting here trying to figure out what happened, so I hope someone here has some advice.

I have done a test in my lab, applied a retention policy to a mailbox and run Start-ManagedFolderAssistant, I can see the policy in folder, look like below:

It proves that I have applied the policy successfully.

In addition, I have found article, in which mentions that Don’t forget that the MFA in Exchange Online runs on a seven-day work cycle, so you can expect some delay here. For more details: Exchange Retention and Communication Compliance Updates

AFAIK the default work cycle for Retention Policy processing by the Managed Folder Assistant in Exchange Online is 7 days. You'll need to wait at least that long or you'll need to manually run the MFA..

You can connect to Exchange Online with Powershell and manually start the Managed Folder Assistant as described at the links below.

https://docs.microsoft.com/en-us/powershell/module/exchange/start-managedfolderassistant?view=exchange-ps

https://www.vootwerk.com/quick-tips-applying-retention-policy-immediately-to-office-365-mailbox/