Block Open in Desktop option from Word/Excel Online on unmanaged devices

Thanks for the response, but the problem is these policies need to work on their own. If I create a policy to block downloads on unmanaged devices, they should work. Any action that allows me to download the file to my local PC should be prevented.

Update: I think you mean an Access policy? According to DFCA "Session control applies to browser-based apps. To block access from mobile and desktop apps, create an Access policy"

So I already had an Access policy setup to block client apps that I was testing but i'm having an issue raised here where it doesnt work for existing installs, only new ones. I tried what you suggested but because my install was already licensed, the file opened successfully.

I'm hoping that I am just doing something wrong, because I cant roll out these policies if they arent reliable.

Thanks.