I think, that is correct behaviour.
If you want to have the feedback just create the event in your own calendar and invite all attendees and the resource.

Which resource? We have created a dedicated resource user for a shared calender, so the shared calender is not held by somebody who may leave the organization. Creating events twice, once in the shared and once in the private calendar is also not directly how this should work.

Here is a usecase, were this is problematic:
We have a shared calendar for examinations. For various lectures, various people schedule the examinations, but do not participate in the event, hence do not want to have the event twice, once in the shared, once in their private calendar. However, these people would like to be informed if the assigned examinors can participate in the examination.

The same holds basically for every workflow with a shared calendar.
Other example: A user schedules an event in a shared calendar, and also invites external people. The external people reply and the messages disappear in the resource users inbox.

Sorry, I didn't get your use case.
A resource user in my understanding is a user which has resource settings for his account (kind, multiplebooking).
This means he will autoaccept invitations, if he is free at that time.

What you mean is a non person account.
Does your admin user for that account see the mails for this non person address?
If not you could share the mail Inbox from the non person account, and delegate his mail address to your admin user.
With that he/she/they could answer questions and see change notifications.

Heho,
sorry for the inaccuracy in notation. Yes, these mails are received. However sharing that mailbox is not an option, especially as this account holds multiple shared calendars for multiple groups of users.

Delegating mail to a single user is also not an option, as again multiple users are concerned, which do not necessarily have access to all calendars hold by the non-person account.

Is there really no way to send out invites as the person who created the meeting/event, and not as the owner of the shared calendar?

AFAIK there is no such option.

But you always can see who acceptetd, by checking the event itself on a regular basis.
First open the event with a double click, then click on the link of the invitees.
All attendees which have accepted, have a green bullet bevor their name. Declines are red.

Would it be possible to implement such a thing as feature request? i.e. make it configurable, from whom the invites are send, either the calendar owner or the creator of an event?

We would definitely vote for implementation of such a feature.

We just migrated from an old Horde to SOGo and it's really annoying for our company not to have the creator of the event as the originator of the invitation.

We also use a non-person account ("office" in our case) which holds several shared calendars (for meetings, business trips, vacation, etc.) where our company members need to create events with invitations to internal as well as external persons and they need to receive the replies to the mail directly. Asking them to check the office inbox in addition would be a major annoyance and also not all that can write to the office calendars are (supposed to be) allowed to access the office inbox.