MS Teams cross tenant chat not working for 2 users

Question

Hi All,

Maybe someone met with such a strange issue.

We have setup External Access in Azure AD, MS365, MS Teams and Sharepoint to allow All domains.

Identity                                    : Global
AllowedDomains                              : AllowAllKnownDomains
BlockedDomains                              : {}
AllowFederatedUsers                         : True
AllowPublicUsers                            : False
AllowTeamsConsumer                          : True
AllowTeamsConsumerInbound                   : True
TreatDiscoveredPartnersAsUnverified         : False
SharedSipAddressSpace                       : False
RestrictTeamsConsumerToExternalUserProfiles : False

Almost all externals can communicate with us apart from 2 users from the same domain.
However, we have another 8 users from the same domain and those 8 can chat using Teams. But when doing a search for the other 2 we get:
We can't setup the conversation because your organisations are not setup to talk to each other.

Well, we clearly can communicate with that organisation as we can chat with remaining 8 users but not those 2.
They were invited the same way directly from Azure AD.

All of them are able to access our Sharepoint with no issues

I'm thinking if there are any prerequisites for them to be visible in Teams. Maybe they need to take part in a meeting first or some direct call.

Any suggestion appreciated.

Answer 1

Hi @PT Maliborski

Does this issue only occur with a certain external domain? If yes, are they in a hybrid deplyoment?

Can these two users search and messages to users in your domain?

Here is a thread with the similar symptom which may be helpful:

Urgent Federation is working in ONe way between Teams only and S4B Hybrid with Teams….

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Answer 2

@Kael Yao-MSFT

Unfortunately 3rd party don't want to co-operate so I informed then after they job is done, I will remove their account and re-invite them again if needed.

Thank you for your help