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

After Windows May update, I had to modify my workaround to prevent Appointments from being  converting into Meetings. I still use Windows 10 Calendar when creating Appointments on my computer, but I switched to using Outlook for iPhone when editing them on my iPhone. After the Update, Appointments started becoming Meetings when edited using Apple's Calendar App. Also after the Update, formatting changes to double-space when Appointments are viewed using Apple's Calendar App.  If you have similar problems, please help Microsoft Community by clicking reply and submitting details of your problem (and your solution if you have one).

Thanks for the update MG.  I am following up to see if I can find out more details on the fix plans.  If I get anything useful I'll post back and share.

Gabriel, today I am continuing to have the problem that Appointments created with Outlook for Desktop become Meetings when edited with Outlook for Web, Outlook for iOS, or the Apple Calendar App. Workaround is to use Windows Calendar App to create new Appointments on computer or use Outlook for iOS (or Apple Calendar App) when creating an Appointment on iPhone or iPad. Today Outlook Support indicated that they are working on a permanent fix.

Are you still seeing the issue today?  I was able to repro it yesterday by creating appointments on my Outlook.com calendar in Outlook 2016 and then trying to edit them in Outlook.com.  When I would try to edit from Outlook.com they would show Send rather than Save.  Today they are correctly showing Save and that is using either Beta or Production UI.  This seemed to be a service side issue because I could repro with old versions of Outlook too.

I use Outlook on my PC and have 365 Account which provides exchange facility.  I have been communicating with Outlook App (for IOS) customer services since mid April on this.  During this time I have found out -

1 - If I create a new item>Appointment whilst in mail and have my Gmail account highlighted, then I can create an appointment that remains an appointment (and can be edited) on the Outlook for IOS App

2.  - If I create the Appointment first in Outlook for IOS App, I can then edit, change & copy within Outlook on the PC and all appointment so manipulated remain editable in the Outlook for IOS App (even the copied ones!)

3 - If I create a  meeting using the standard method of clicking within the calendar on PC outlook and send this to one of my other email accounts as a participant, it become an editable appointment with Outlook for IOS APP - i.e the exact opposite of what occurs with an appointment creation with Outlook PC.

It would appear that in transferring between Outlook PC / Exchange / Outlook for IOS App the meetings & non-meetings appointments are being transposed?