What would cause a private channel to no longer be visible in a Team?

[DazzaR]

I ran a PowerShell report to find private channels in our tenant. I spotted one I thought I'd deleted months ago. It's not visible in the Team UI or via Team settings. It was a demo Team with two of my accounts, one still had access (to the SharePoint site) but also couldn't see it and the other couldn't see it and couldn't access it. 

When I went to the SharePoint site for this private channel and clicked around it, it appeared to work. When I clicked from the site to 'go to channel conversation' it just comes up with this message. 

Thanks

[#2 · Accepted solution]

The issue is the attached SharePoint sites to Private channels do not seem to get removed, especially if you have retention policies set on SharePoint sites as a whole it will be retained even with the channel removed. I'd check that you don't have your tenant Sites on a retention. If not could just be that they do not get removed when deleted, but I have a retention on so I expect my SharePoint content to not go away.

[#3]

@Chris Webb thanks. We don't have a retention policy. 

Seems to be mixed info on this. Some articles suggest the SharePoint site belonging to a private channel is deleted. In my case I'm pretty certain I deleted the channel and the SharePoint site lives on and this was easily over 30 days ago.

From Avepoint guide on Private Channels

• Private channel site collections live and die with their associated channel, so you should not have to worry about the “lifecycle” of these sites separate from the channel. When a private channel is deleted in Microsoft Teams, all of its assets–including the SharePoint site collection–are deleted as well. Teams will allow 30 days for the recovery of that private channel, and if recovered through Teams, the site collection will be restored as well.

EDIT: Someone elsewhere kindly pointed out that deleted sites go after 93 days. Seems obvious in hindsight. I blame my lockdown-addled brain.

https://docs.microsoft.com/en-us/sharepoint/restore-deleted-site-collection