I just bought Office 2019 for Mac, from Microsoft's website

Whenever I log in, it asks me to activate

The first time I try, it gives me an error message that it can't activate at this time

Then I click 'log in using another account', log in with the exact same login details, and it works

But whenever I close the program, the same problem happens again

This seems to be a problem with Office, not Mac. All of these error messages happen within Office, and Office manages to activate the second time around

Not what I expect having just paid £250 for software!!