A fully managed end-to-end service for digitally signing code, documents, and applications. (formerly Trusted Signing)
Here is the solution for others who may run into the same or similar problems:
The primary issue related to using a 4-5 year old Android phone. Apparently, older versions of Android are unable to complete the required step to share a verified ID from the Microsoft Authenticator app to the receiving page on the desktop browser via the QR code. The Authenticator app simply shuts down, crashing back to the home screen without any error message nor any presented alternate option to forward the ID in a different way. Following AI advice and various other posts around the internet, all alternate options also failed along the way at one point or other (including copying and pasting URL's directly in the mobile browser to try and bypass certain QR steps, finding an alternate link on the receiving page that does not require a QR code when using a different web browser like Chrome or FireFox, and several others). What ultimately had to be done was going through the entire identity verification process again from scratch on an entirely different Android phone using a newer version that could handle one of the QR requests. The newer phone (~1 year old) was still unable to complete the step that requires launching the Microsoft Authenticator app via a QR code (only wanting to copy the QR link to the clipboard or display it), but manually launching the Authenticator app and then routing through various links and QR codes from within eventually allowed the steps to complete.
The problems with this system are extensive, layered, and compounded when one step in the process fails and there is little to aid the user in finding alternate solutions (there are often none). The problems I encountered during this process include inconsistent behavior when selecting options (example: selecting an option the first time fails, the second time it works), limited or entirely unclear/missing directions on methods and procedures (example: 60 day window limit on identity validation renewal process, yet the renewal notice arrives prior to this timeframe), incompatibilities on dependent external hardware (older Android devices), and no alternative solutions when encountering unsolvable problems preventing further progress.
This is a very convoluted, complex, and unnecessarily incompatible process to have to go through. Please either keep everything on the web browser side of things or the mobile device side of things and do not require QR exchanges between the two that apparently many phones are not capable of handling with the methods Microsoft is requiring. Too many elements are already unnecessarily sharded and separated (ie subscription, Azure+Entra, roles, etc). Please consider more unification and simplicity in the future. Additional guidance and clear instructions with alternate solutions would also be a huge help. The time spent (wasted) on sorting through problems like this deplete productivity and is excessive.