I had the same problem but I was able to solve it.
BBpress controls the number of allowed URLs with WordPress settings.
Open WordPress settings, go to “Discussion”-> “comment moderation” item, and set the upper limit of pending URL.
If you enter a very large value, this problem will never happen again.
This idea was discovered by following in the “bbp_new_topic_handler” function.
The function called the “bbp_check_for_moderation” function, and finally used the “comment_max_links_url” filter to obtain the number of pending URLs.
