Cannot use mitmproxy or other service while using Nintendo Switch Online App

[redpwilliams]

When trying to log into the Nintendo Switch Online App, an error message pops up: Communication Error: The Internet connection is unstable. Make sure you are connected to the Internet and try again. With an Error Code of 2817-0599

First I used mitmproxy and charles, and when those didn't work I switched to mobile services like HTTPCanary/HTTP Sniffer Capture/Analysis for Android (basically the same thing as mitmproxy and charles, just all on mobile. No luck with that.

I also tried using mobile data instead of a solid internet connection, the same issue occurred.

While I was using these services, I could visit other sites, just not log into the Nintendo Switch Online App.
Any thoughts?

[frozenpandaman]

mitmproxy will not work on Android 7.0 or above due to reasons I explain here. Use iOS (which I think should still work?) or an Android emulator if you need.

What's your goal in capturing the traffic though, or to what end are you wanting to mitm the app?