Shared mailbox automatic reply being turn off automatically

[Don_Vlogeer]

There is one shared mailbox we enabled the automatic replies with no end date, eventually the automatic replies will automatically switch to "don't send automatic replies" after 1 month or so. 

Anyone have seen this behavior, we are using exchange 2016 CU23. this is an unattended shared mailbox and occasionally people will check it. 

Please help to shed some light and thanks in advanced. 

[#2]

Best check the audit log.

[#3]

You can reset OOF automatically once a week, for example, using Exchange PowerShell in combination with a scheduler.