On a new edge transport server in exchange 2019 (the only one)

EdgeSync service cannot connect to this subscription because of error "The LDAP server
is unavailable.".

We are seeing:

[PS] C:\Windows\system32>test-edgesynchronization


RunspaceId : bc3a45ec-d76b-44b3-a07b-9a9ad68074ec
SyncStatus : Failed
UtcNow : 16/01/2021 14:55:48
Name : TShub
LeaseHolder :
LeaseType : None
FailureDetail : EdgeSync service cannot connect to this subscription because of error "The LDAP server
is unavailable.".
LeaseExpiryUtc : 01/01/0001 00:00:00
LastSynchronizedUtc : 01/01/0001 00:00:00
TransportServerStatus : Skipped
TransportConfigStatus : Skipped
AcceptedDomainStatus : Skipped
RemoteDomainStatus : Skipped
SendConnectorStatus : Skipped
MessageClassificationStatus : Skipped
RecipientStatus : Skipped
CredentialRecords : Number of credentials 0
CookieRecords : Number of cookies 0



[PS] C:\Windows\system32>start-edgesynchronization


RunspaceId : bc3a45ec-d76b-44b3-a07b-9a9ad68074ec
Result : CouldNotConnect
Type : Recipients
Name : TShub
FailureDetails : The LDAP server is unavailable.
StartUTC : 16/01/2021 14:56:05
EndUTC : 16/01/2021 14:56:05
Added : 0
Deleted : 0
Updated : 0
Scanned : 0
TargetScanned : 0

RunspaceId : bc3a45ec-d76b-44b3-a07b-9a9ad68074ec
Result : CouldNotConnect
Type : Configuration
Name : TShub
FailureDetails : The LDAP server is unavailable.
StartUTC : 16/01/2021 14:56:05
EndUTC : 16/01/2021 14:56:05
Added : 0
Deleted : 0
Updated : 0
Scanned : 0
TargetScanned : 0

Any ideas?

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If the domain in the certificate is the same on each it appears to cause this error even if the certificate thumbprints are different.

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