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

Appointments changing into Meetings recently became a problem for users of Outlook.com accounts and Microsoft Exchange users. It results from glitch with April 2018 update to Office. Workaround is to use Windows Calendar App (instead of Outlook 2016) to create appointments on PC.  Until glitch is fixed, Outlook 2016 can only be used to view or edit Appointments -- not create them. Outlook for iOS and Outlook for Android can be used to create or edit appointments. See following post for help using Windows 10 Calendar.

WINDOWS CALENDAR

https://support.microsoft.com/en-us/help/14091/windows-8-calendar-app-help

I have Office 365 on my PC sync and it to my Galaxy S7's Outlook for Android app.  No iOS app owned by me.

As others have said, when I create an Appt on my PC in Outlook it appears as an uneditable Meeting on my Outlook for Android app.  If I create an Appt on my Android app, it works fine, UNTIL I edit it on my PC's Outlook, at which time it becomes corrupt.

The duration of this bug with no solution from MS for months is definitely very frustrating!

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.