@Cloud_Geek_82 Thanks for your quick reply. Please check whether "TMWKY" is the last 5 characters of your MAK key. Besides, I would suggest you disable sharedcomputer activation to have a check, as SharedComputerLicensing property is uesd for Microsoft 365 Apps, which is licensed on a “per user” basis, but Office 2019 is licensed on a “per device” basis.
Step 4. Change your product key. Enter the Office 2016 or Office 2019 of your choice and simply click the Install this product instead option. If this is a new product key, you will be prompted to redeem the key; to do this, simply follow the on-screen instructions. Your Office application (s) are being updated now. soMNT56.