Outlook calendar 'changes' appointment into a meeting after editing.

I share your disappointment/frustration about Microsoft delay to fix Outlook glitch.  This week I had another glitch - the OneDrive App mysteriously disappeared from my laptop the same day that Microsoft pushed out the June update for Windows.  I just now submitted Feedback to Microsoft to suggest that they reduce software glitches by reducing the frequency of updates.  Please upvote my Feedback if you agree - you can find the Feedback by using Windows Feedback App and search for the word "Update" (which is subject that I used for my Feedback.

Re: Outlook calendar 'changes' appointment into a meeting after editing

Question: how can it take ~3(+?) months to fix something that was previously working fine? Not possible to roll-back the change that broke this until it's actually fixed?

Below are comments related to problem with Outlook.com that originated this thread, 2) new problem with Windows 10 Calendar mentioned in AJ's post on 6/11/2018, and 3) Microsoft's recent Update to Windows 10.

OUTLOOK.COM

As workaround, I am currently using Windows 10 Calendar (instead of Outlook for Desktop) to create calendar items on my laptop and I use Outlook for iOS to edit or create them on my iPhone and iPad.  My workaround is somewhat different from following note posted on May 2, 2017 to Microsoft's Support Page for Office: Currently, you can't use Outlook on Windows to edit calendars that are shared with your Outlook.com account, even if you've reconnected your Outlook.com account to Outlook. We're working to make it possible to edit shared calendars in Outlook 2016 for Windows. To edit a shared calendar, go online to your own Outlook.com calendar, open Calendar for Windows 10, or use a mobile device. Read how to Add your Outlook.com account to another mail app.

WINDOWS 10 CALENDAR

I don't have the "appearance" problem, but that might result from my limiting use of Windows 10 Calendar to my Outlook.com account (not for my Gmail or iCloud accounts).  When I move items on Windows 10 Calendar, appearance will lighten if the item is moved to a date that has already passed.  Suggest you submit Feedback to Microsoft if appearance of moved items continues to lighten even when date hasn't passed. To submit Feedback, type "Feedback" in Windows search box to open Windows Feedback Hub.

WINDOWS 10 UPDATE

If you haven't yet done so, use Windows "Check for Updates" Tool to install the May 2018 update Windows 10, version 1803. Although it doesn't fix Outlook.com's Calendar issue, it does add improvements and makes other fixes for Windows.

There is one more thing. I have a gmail account as Apple account that does not match with my Windows account (hotmail). Maybe this has something to do with this bug because if I create an event in Outlook 365 desktop starting from my gmail account everything works flawlessly.  I mean that the event created starting from my gmail account in Outlook 365 desktop does not turn into a meeting when edited with my iphone. I haven't tried changing my Apple account to match my Windows account (hotmail) to see whether this is sorted though.

Yes, it also happens to me. Still when I close the Windows embedded Calendar and open it again later on, the event returns to "normal".

That's weird - I'll check that..... Thanks.