Visio pro for Office 365 - WARNING! It may not save your work properly

I just spent 10 hours creating a diagram for an important project.  

I have been frequently saving the project and exported to PDF and exited the Visio. (there was no warning or anything.)

I opened the file again to make minor changes.... boom all the changes I made for 10 hours are gone.  (it didn't save for some reason.)

I strongly suggest not to trust this software. (be careful when you want to use this for a serious work..)

I am using Microsoft Visio Pro for Office 365 (Version 1705 Build.8201.2200) on Windows 10 pro (10.0.16299.64)

bufuro