Symptoms: User continued to have issues opening word or excel from SharePoint. At times it would ask for credentials, you would enter a username, then the screen would disappear without a password request. Other times it would open, but would not let them edit the document.
Sorry, we can't get to your account right now. To fix this, please sign in again.
The root cause was the TPM. However, the root cause of the TPM messing up is unknown, I didn't see the need to dive into it as the user did not benefit from having it on.
A temporary fix was to reset the TPM in windows:
-> Start menu search
-> type and click on "Windows Defender settings"
-> click Device Security
-> click security processing details
-> click security processor troubleshooting
-> click clear TPM
The permanent fix ended up being to disable the TPM Module in the BIOS Completely.