Hello everyone!
I'm having issues with Office 365. Everything works OK with my code, even on Gmail I get a decent mobile version, but it all goes wrong when you open it on Office 365. It seems OK when using a single column, but not with 2/3 columns layout (1 in mobile)

You can see code and test here:

https://litmus.com/builder/831c102

Do you know any sources I can follow to fix it?
Any help will be deeply appreciated.

Thanks!!!