When a user submits the form on my website www.metutel.com, a pop up "Are you confirmed?" appears and they are unable to submit.
We can see you're using Post Grid Combo to create your web pages.
Good luck with that!
But please note this plugin is under development and has issues. Feel free to post any bug report or feature request. We'll update our plugin ASAP.
Welcome to PickPlugins
You are probably talking about Form Wrap block, I am trying to fix the issue by removing the option "Submit Confirm" from On Submit, please see the screenshot.
Please update the latest fixed version from GitHub and reinstall the plugin, we will soon update on wordpress.org