Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
It's hard to say wether or not this is the reason that my issue resolved but I realized that I had not enabled multi-factor authentication in my org settings for my email account (M365 Business Basic). It worked on first try after changing that setting after days of trying.
Could be a coincidence but worth a try if you haven't already done so and use a Microsoft 365 env for your business.