First press F12 and watch your console for errors etc etc.
And second enable WP debug to a log and after a while check it for errors.
https://wordpress.org/support/article/debugging-in-wordpress/
Invest a little time to learn the basics, you will need them in the future.
wpForo has some tools and check for errors. Database and debug. Are they reporting anything?
And do you have ANY other tools / plugins that could interfear with WP? Any security plugins or services?
Do you see any errors in the following tabs:
- Dashboard >Forums > Tools > Debug > Tables
- Dashboard >Forums > Tools > Debug > Errors & Issues
Do you see any error message when the topic/post is not saved?
Can you do a test reply here with the same content you post in your forum?
Have you tried to post it using a Desktop pc?
I don't see any issue in your forum. We just registered and check. We've left test topic and posts without any issue. In any case, please go to Dashboard > Forums > Settings > General Tab, make sure your forum Base URL is correct and click the [Update Options] button, then delete wpForo cache in Dashboard > Forums > Dashboard admin page.
Try posting the word Omeprazole, it doesnt open a topic, i dont get why it denies certain terms please