This kind of issue is usually caused by either conflict with other plugins or the active theme. It seems one of the active plugins also uses the comment_text hook and adds the < strong > tag in the comments section.
Please deactivate the plugins/theme one by one and check after each deactivation to find the problem maker.
Keep the cache plugin (if you have) deactivated during this testing process.
Please don't forget to press Ctrl+F5(twice) on the frontend each time before checking.
In case you want to say thank you! 🙂 We'd really appreciate if you leave a good review on the plugin page. This is the best way to say thank you to this project and the support team.
