Issues Logging into Outlook and OneDrive on Windows with Claro and Movistar in Colombia?

Hey everyone! I'm dealing with a frustrating issue trying to sign into Outlook and OneDrive on Windows (all versions from 7 to 11) while using Claro and Movistar networks in Colombia. I've noticed a few common patterns and wanted to reach out to see if others are experiencing the same thing or if anyone has insights into what's going on.

Here's what I've found:

- This problem usually pops up when sharing internet from a Claro phone to a computer, whether through tethering or a hotspot.
- It also shows up on Claro and Movistar home networks, particularly with certain equipment like coaxial modems for Claro and fiber optics for Movistar.
- Importantly, this issue only affects computers, as phones seem to work just fine.

### Error Behavior:
1. You can access the login page without issues.
2. After entering the email and password, things go downhill:
- Sometimes you get sent back to the login page.
- Other times, it seems like everything is working, but you just end up looking at a blank page.
- On that blank page, an error might pop up saying something like, "Please retry with a different device or other authentication method to sign in."
- This links to a general page about a 400 error, though that specific code never really shows up.

### What I've Tested:
- I've tried multiple devices and browsers.
- I've ruled out problems with credentials, local settings, or security software.
- I can access everything just fine on my phone using the same networks.
- Interestingly, using the Psiphon VPN resolves the issue, but it introduces complications with certain secure sites like banks.

### My Current Theories:
- There could be DNS or proxy resolution issues.
- There might be some interference with how OAuth authentication works.
- Authentication handshake failures could also be the culprit.
- Network redirects might be mismanaged, disrupting session flows.
- Home networks might have restrictions or errors affecting access, unrelated to public or mobile networks.

So, if you're also using Claro or Movistar, have you faced similar issues accessing your email? What kind of error messages are you encountering after logging in? Any successful workarounds or ideas on what might be going wrong? I'd love to gather more information and help others facing this issue too! Thanks a lot!