Unable to open office files in Sharepoint Web

Hello Everyone, wanted to check is anyone having the same problem. I this thread i'll use powerpoint office files as example, but this happened on all office files. I tried in IE, Chrome and Safari (iPad/iPhone).

Problem:

Whenever you clicked on an office file from SharePoint Web, it just doesn't launch anything (i.e. no response at all), no error message or any kind of prompt.

The issue only happen on Account A, on Site X (App), and on a non-company issued device (both personal laptop, iPad and iPhone). Understand personal laptop is not allowed as company policy will not allow user to login office client in non-company issued device. But the question here is why iPad and iPhone can't launch the file where there is already MAM in place? 

More Detail for your understanding:

I've two accounts within the same tenant, Account A and Account B, the differences are:

• Account A: Licensed, Conditional Access Policies Applied
• Account B: No license, no Conditional Access Policies 

I've two sharepoint site, Site X and Site Y, the differences are:

• Site X (App): Default open behavior is set to "Open in Application"
• Site Y (Web): Default open behavior is set to "Open in Web"

I've two type of devices,

• Company issued device (Laptop), and
• non-company issued device
  • personal laptop
  • iPad/iPhone - regulated by MAM

Test Conducted: