Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Guys, something to consider, might have much impact but take a look at the number of device you have activated your office suite if it is of Business/Enterprise Class (such as Microsoft 365 Business Standard)... Microsoft warrants the installation on maximum 5 device and will refuse to activate other suites if you have exeeded the number of activation.
You must goto your portal.office.com and disconnect additionnal office connected to your account. This can help solving the issue...