According to a conversation on Twitter, the TalkBack team at Google changed the way they are handling flicks left and right, which is no longer compatible with the way Firefox handles them. Their current "workaround" is to emulate the older behavior with the Firefox release, but beta, Aurora and Nightly are broken. We should instead work with the TalkBack team to get proper implementation details so we can mutually support each other across the board again. Whitelisting is the worst of all solutions and should be avoided if possible.
TalkBack team has been contacted directly (thanks Marco). I provided them with all our package names for our release channels. We will need to revisit the Android a11y API now that it has matured and provide better native support. But that goes beyond the scope of this bug.
Eitan - Is this something you should be assigned?
This is something that will hopefully be resolved on the TalkBack end. Keeping this open to track.
Eitan, what's the status here?
They ended up making an exception for Firefox. So it is fixed in TalkBack. Anyway, we are in the process of modernizing our a11y implementation.