Spam meeting invitations filtered by Outlook still appear in Apple Calendar via Hotmail sync and cannot be deleted

I am experiencing a recurring issue with a personal Outlook.com/Hotmail account synchronized with Apple Calendar on an iPhone.

Spam emails containing meeting invitations are apparently being filtered or removed correctly by Outlook, but the associated meeting invitations are still being exposed through the Hotmail calendar synchronization to iOS.

The sequence is:

A spam email containing a meeting invitation is sent to my Hotmail account.

Outlook filters/removes the spam email. It is no longer present in my Inbox, Junk Email, or Deleted Items.

The meeting invitation/event does not appear anywhere in Calendar on Outlook.com.

Despite this, the invitation appears in Apple Calendar on my iPhone, associated with my Hotmail calendar.

Opening the event in Apple Calendar only provides Accept, Maybe/Tentative, and Decline.

There is no Delete Event or Report Junk option.

I do not want to select Decline because I do not want to send a response to the spam sender or confirm that the email address is active.

The unwanted invitation remains in Apple Calendar even though neither the original email nor the event can be found on Outlook.com.

I have confirmed that this is not an accidentally subscribed calendar. The unwanted events are shown as invitations belonging to my normal Hotmail calendar.

Removing the Hotmail account/calendar synchronization from the iPhone and adding it again can remove the existing invitation, presumably because the local calendar data is rebuilt. However, this is only temporary. When another spam meeting request arrives, the same problem occurs again.

I contacted Apple Support. Their response was that, because these invitations originate from Hotmail, Apple Calendar only displays the actions made available through the Hotmail/Outlook calendar synchronization. They advised that prevention or removal of these invitations therefore needs to be handled on the Microsoft/Hotmail side.

What I am trying to achieve

I need to continue synchronizing my Hotmail calendar with Apple Calendar/iOS. I therefore cannot simply disable Hotmail calendar synchronization.

Is there a way in Outlook.com/Hotmail to:

prevent meeting invitations from unknown or spam senders from being exposed through calendar synchronization;

prevent a meeting request from being synchronized when the associated email has already been classified as spam;

delete or purge these orphaned meeting invitations from the Hotmail/Exchange synchronization data without sending a response to the organizer; or

disable automatic processing of external meeting requests while continuing to synchronize normal Hotmail calendar events?

The particularly confusing part is that Outlook.com itself shows no such calendar event, yet the Hotmail account continues to provide the invitation to Apple Calendar.

This appears to suggest that the meeting request remains somewhere in the account's calendar/invitation synchronization data even after Outlook has filtered or removed the corresponding email.

Is this expected behavior for personal Outlook.com/Hotmail accounts, a known synchronization issue, or is there an account setting that can prevent it?