Hello forum! A first-timer here.

I have recently purchased and installed Microsoft 365 Personal. The installation seems to have worked without issue, however, I am unable to use (for example) Excel or PowerPoint.

When opening Excel, I am asked to 'Sign-In or create account'. Clicking this button opens a new 'Activate Office' window asking for my email address.
When I type in my email address and hit return I am immediately sent back to the initial 'Sign-In or create account' screen; forever stuck in the loop.

This first screen does have an alternative option to enter an Office product key - which I have also tried (the key I was issued with at purchase time) - yet this also takes me to the same 'Activate Office' screen as well.

Having done a little research into this interminable loop issue, I have followed guidance to remove any references to Office in the the Credentials Manager, however, this has not resolved the problem.

Many thanks in advance!