Sending email to distribution group and shared mailbox from person/group field in SPO with Azure Log

I have a document library in SharePoint Online (SPO) which contains a column from type "person or group" for assignment. This person/group field is set to allow multiple and is set to allow groups. Based on the made choice from this person/group field an email with Logic Apps should be sent to the assigned elements, which could be one or more of this three:

• person user: This functions well so far. No support is needed here.
• distribution list: I can choose distribution lists and an email is sent to them, but the recipients of the email do not receive the email. I have put my person user and one distribution list and I can see in the recipient line of the email that the distribution list is displayed correctly with all members of the distribution list. What could be the problem, that the recipients do not receive any email?
• shared mailbox: When I chose a shared mailbox in the person/group field then I receive the message "No match was found.". What could be the problem here?

I hope somebody can help me with the distribution list and shared mailbox issue and can tell me if the root cause of any of this problems is on side of Logic Apps or SharePoint. Thanks in advance for any assistance.