Discussions and help can be found Telegram, Signal or Matrix. Other services we do not trust and/or not proven themselves good enough to be used for communication.
Telegram is a cross-platform messaging service, clients are open-source (server is proprietary). Also messages are not encrypted by default, secret chats are encrypted.
Join the official Telegram group.
Signal is an open-source, encrypted messaging service for instant messaging, voice calls, and video calls.
Matrix is a decentralized, open standard and federated communication protocol. You could use the web client, or install one of the many Matrix Desktop clients on your computer (like the Element Desktop client). Or even host your own Matrix server (Synapse) and become part of the federation. Both of which are open-sourced. Messages can be end-to-end encrypted if desired.
Matrix is decentralized, this means that in addition to the official matrix.org server, you can also register an account on other homeservers.
My homeserver URL is open for public registrations: https://matrix.melroy.org.