Salesforce Event Attendees not receiving invitation email

Question

Requirement: when a Salesforce (SF) User creates an Event and adds Attendees (Contacts) on that Event, each Attendee should receive an invitation email enabling them to add that Event to their respective MS-Outlook or Google Calendars.

Salesforce documentation states that only when creating the Event from SF Classic such invitation emails are being fired from SF's servers (I have tested that from Classic and it works indeed).

But, when the Event is created from Lightning Experience, SF servers will NOT fire these emails and... for that email to be sent, the user creating the Event should have access to the integration between SF and MS-Outlook through Einstein Activity Capture and it is actually MS-Outlook who will send the invitation email.

I have setup Einstein Activity Capture and integrated SF with MS-Outlook and eventually performed the test (creating an Event with Attendees from LEX UI) to verify if the invitation emails are being sent. But, no (invitation emails are NOT being sent). I have also performed the same test with an integration between SF and Google through Einstein Activity Capture but have got the same result (no invitation emails are being sent)

Have you faced this issue before? Can you help?

Thank you very much.