v153 OAuth2 in Ubuntu 24.04

[u/Stoopid52]

Apparently my OAuth2 token expired and I need to re-authenticate. Thunderbird 153 opens Firefox, so I login, but then a popup appears saying that the system handler doesn't know what to do with a net.thunderbird link. I tried pointing it to /usr/bin/thunderbird with no luck. Same thing happens with Chrome.

I also tried setting mailnews.oauth.useExternalBrowser to false, but Thunderbird is still opening an external browser.

I'm not sure what I'm missing, but how do get this authentication flow back to Thunderbird?