Since yesterday, we have big display issues on Outlook and I need help to understand what's happening !

It appears that Outlook shows a broken responsive version even if I'm on my desktop.
Our templates are used since a few months minimum and we've never had problems before; and I see that emails received from anothers compagnies are broken too, so I'd say it doesn't come from my Html.
Our IT said that Microsoft didn't make update lately, and on the others webmailers (Gmail, Yahoo, etc), there's no problems.

I can't identify the probleme because it only appears on a few laptops with Outlook 2013 , but not every ones, and a few Outlook 2016 as well. And for the people who have the problem on their desktop application, there's the problem on the Office 365 version too.
Does anyone have any idea ?