Dear anyone,
Your duolingo forum registration isn't automaticaly transferred to duome forum so in order to join duome forums you need to register with your existing or any other username and email; in any case it's advised that you choose a new password for the forum.
~ Duome Team
The speech services by Google were the issue. They were disabled. After enabling them and restarting my phone, everything works now. I had seen Google needed microphone privileges but hadn't seen Google speech services needed it as well.
Thank you very much!