Installed Exchange 2019 on-prem into an existing Exchange 2016 environment. I've created a couple of test mailboxes which exhibit these symptoms:
-Mailbox connects in Outlook desktop client.
-Mailbox disconnects & reconnects several times
-Eventually it moves into "IsQuarantined" state
If I remove the mailbox from quarantine the mailbox eventually causes the database to dismount and fail over to another server.
Just before the DB crash I see:
Event ID 1013
The mailbox with mailbox guid c96c42c0-8ba2-456e-b0db-0e05cfb59d85 caused a crash or resource outage on database DB (47d62239-9667-46d6-a744-0aabe2f0d938).
I've confirmed that only .NET 4.8 is installed. TLS 1.0 and 1.1 are disabled. I can access the mailbox from within my Exchange 2016 account in Outlook without issue. Am I looking at an AV conflict or something else?