Assalamu alaikum Ustadh. Is joining communities where students of knowledge participate and share reminders and ask questions permissible? It's not segregated

Ask whom? The one answering must be a person of knowledge. We must also understand as well that these things lead to fitan not just fitnah. If it is a mixed group I heavily warn against this as how can we guarantee that all these males and females r trustworthy and they would not transgress the boundaries set by Islam.