I have exactly the same issue.

It show that annonymous users have create items permissions, maybe this is what is causing the issue?

A while ago i created a script of my own that works ok.

First of all here the client access permissions of the sating folder:
Get-PublicFolderClientPermission Non_IPM_SUBTREEStaging

FolderName User AccessRights
---------- ---- ------------
Staging Default {None}
Staging Anonymous {None}

# Create Public Folder in hidden staging subtree
New-PublicFolder -Name "$PFFoler_Name" -Path "Non_IPM_SUBTREEStaging"

# Move to Visible Tree
Set-PublicFolder -Identity "Non_IPM_SUBTREEStaging$PFFoler_Name" -Path ""

Hello,

What are your permissions?

as for me i can't reproduce the issue however my folder, anonymous is set to none on

for my public folder of my organization default is none, anon is non, and only my security group has reviewer.

Please note that on mail enabled public folders the permissions will need to be different.

I also heard that for some people there's a slight delay after creating a new account (so they can temp see everything, but after a few minutes / outlook restart only their own PF remains visible)

When it finishes it has the same permissions but with anonymous has create items (maybe it is for mail purpose).

I think it would be a better idea to make the first public folder not mail enabled.

Anonymous with create items is indeed required for mail enabled pf normally.

however that shouldn't be set on the first pf or the root PF of each org.

Well, that is exactly what happens.

The first PF is mail enabled and has these rights.

Created a new customer (test03) with Hosted Exchange

Ran the following command:

Get-PublicFolder -GetChildren | Get-PublicFolderClientPermission | ?{$_.User.UserType -eq 'Anonymous'} | FT Identity, User, AccessRights -auto -wrap

Got this result:

Identity User AccessRights
-------- ---- ------------
test03.nl Anonymous {CreateItems}

All my other public folders have at root level:

Anonymous {None}