iPhone Exchange Calendar Sync of a Google Calendar invitation

I have a fully updated iPhone 12 (15.3.1). I have a Microsoft Exchange account that I use for my main Calendar and Contacts repositories. I have various email accounts using various services (Exchange, Gmail, IMAP) but I do NOT have Calendar or Contacts enabled for any accounts other than the aforementioned Exchange account.

My issue is when I receive Calendar invites on non-Exchange email accounts, I can add them to the Exchange calendar on the phone, but they never get synchronized to the server and subsequently don’t show up on other devices. It works ok if I receive the invite through any Exchange account (including those without Calendar enabled on the phone). If I add the invite to the iCloud Calendar, it synchronizes. This is the only way I can get it into Outlook on my PC to then move to my Exchange Calendar, but this is cumbersome and prone to error.

Is something I can do to get these items to sync to my Exchange Calendar? Thanks!