I am an occasional participant in: Christianity. " Like any library, Christianity Stack Exchange offers great information, but does not offer personalized advice , and does not take the place of seeking such advice from your pastor, priest, or other trustworthy counselor." The format of this site is, more or less, you ask a question or pose a query, responses are given, and the responses are “graded” by viewers. Rambling debate is discouraged.
A second forum that I have seen but not participated in is a spin-off of: “Early Christian Writings”. The forum itself is at: Biblical & History Forum. I am least familiar with this site. Peter Kirby, the brain behind the Early Christian Writings site and the Biblical & History Forum, also has a Twitter Feed https://twitter.com/mrpeterkirby AND a blog: https://peterkirby.com/.
Unfortunately, I’m the only person who would be interested in a forum that I started, which would leave me in the position of having “peerless review” and moderating any exchanges between me and myself.