@mentions in Powerpoint for Mac

I have shared a Powerpoint file in One Drive with a colleague. When I open this file online or in Teams, I can use @mentions in comments to highlight a task.

However, when I open it with the Desktop app I can see the other person working in the file, but I am unable to use @mentions. It simply states the person could not be found, even though the file is shared correctly and I see them working in the file. I am using Powerpoint for Mac 16.46 on Cataline 10.15.7

What else can I try? Shouldn't this work in the desktop app as well?