Hi

Twitch officially supports the latest two versions of Mozilla Firefox. Twitch Help Center

1. Browser Extensions may cause that. Restart Firefox in Troubleshooting Mode. This temporarily disables all extensions and custom settings. Go to the Firefox menu > Help > Troubleshoot Mode... If you can log in this way, one of your extensions is the culprit. Disable all extensions then try logging in. Re-enable them one by one to find the conflict.

2. If Enhanced Tracking Protection in Firefox for desktop is set to Strict or Custom with strong blocking, try setting it to Standard.

3. Cookies and Site Data

4. If you are using a VPN, Proxy, or DNS-level ad-blocker, temporarily disable it and try logging in.

Tried running it in troubleshoot mode, still no log in While in troubleshoot, verified that enhanced tracking protection was standard. it was wiped cookies, still broken Pihole disabled, still broken

Verify your timezone setting on your Ubuntu system.

If it's set to a generic or incorrect time, try setting it to your specific local timezone (e.g., Europe/Athens instead of just a UTC offset). I had a similar issue and it was solved like this. You can try it.

I just switched to manual time zone, same issue, not letting me in.

Ook ​I recommend trying the Flatpak version of Firefox.

Thank you! Flatpak version works. Not sure what is wrong with apt though

Same issue here. Tried everything above. Currently only way I got this working was to use Firefox under a Windows 11 VM. (I don't have flatpak on my distro)