Azure Directory Sync not detecting public folders

Hi Folks,

I've been trying to use every and all features of Central Email Advanced, mainly to use my office as live Guinea Pigs before pitching the product to clients.

So far so good with the exception of the Azure AD sync is unable to pick up any public folders on our 365 tenant.

Bit of background which might be an issue or a red herring, I've yet to figure out which.

2017 - we used the email central with our on-prem exchange and stopped using it when we migrated to 365 - we also used the local AD sync tool for users.

Our Central Email platform has all our public folders listed as created in 2017/2018 etc. and I am unable to delete or edit them at all.

Fast forward to 2021, we now use the platform again with Azure AD sync but it cannot pick up any *new* public folders, all the historical ones still exist and accept email but any new ones since we originally used it aren't and are currently causing NDR's and we're not receiving reports.

Don't ask why we're using public folders for it, there is a very technical reason 

Anyway, as a work around I've manually made 1 public folder on Central Email and put in a whole list of aliases on addresses we need to receive and it's doing the job as a workaround but it's not a solution and I'm just as concerned that we might have this issue with other clients who also use a public folder on 365.

Anyone have any ideas on how to get Central Email to pick up public folders? Sophos Support say their system is OK and have provided logs to show this, other than it can't see any public folders I am concerned to why the old ones from 2017 are there.

If I could edit the old 2017 created PF's on Central Email then I wouldn't be so worried but I can't.

At the bottom of the log that support sent me was this - there were several lines of it and I've removed OID and UUID as they're confidential.

Jul 26, 2021 @ 20:42:06.065 skipping corrupted record { "_id" : { "$oid" : "xxxxxxxxxxxxxxxxxxxxxxx"} , "_type" : "Directory" , "c" : { "$uuid" : "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"} , "created_at" : { "$date" : "2016-09-14T10:56:56.138Z"} , "name" : "Local Directory" , "name_lowercase" : "local directory" , "search_tokens" : [ "local directory" , "directory" , "local"]}

Not sure what it means but it doesn't look healthy, not sure if the local directory means the old sync we did years ago or Sophos' own local directory of our tenant.

Ta

Ian