Hello,
Is your Office was originally installed under your old account before you joined the Family plan again?
If Word and Excel still show “Unlicensed Product,” I recommend signing out of all accounts in any Office app under File > Account, restarting your computer, then signing back in with your new Microsoft account linked to the Family subscription.
If the sign-in page does not load, check your internet connection and make sure you can reach https://login.microsoftonline.comin a browser.
If activation still fails, Microsoft’s support article “Unlicensed Product and activation errors in Office” gives the latest official steps to fix activation issues.