Something is not right with caching. I can't comment when logged out (admin)
Every time I log into wordpress I can comment, but when I log out every time it is impossible.
I tried to clean the cache. It gives no results. I use Fast Velocity Minify, Cloudflare and WP Fastest Cache.
I also tried to comment on other browsers. No effect.
This is my site (please do not spread urls but hide into insert link option).
Here are my options from these programs (Polish language)
In Cloudflare i used Brotli, ttl 6 months, standard caching and page rules.
For some reason, jQuery is not defined for the guests. If you deactivate the plugin and it works fine you should contact the plugin support forum and ask them to fix the issue.
The plugin either doesn't load jQuery for guests or jQuery is being loaded later then wpDiscuz js files.
Thanks to your mention of jquery. The problem was conflict Fast Velocity Minify conflict with wpdiscuz. In the general settings you have:
Combine JS and CSS Files to Optimize Page Loading Speed
Minify JS and CSS Files to Optimize Page Loading Speed
I have turned off these options and everything is going fine.