Hello, @worddev
I can understand the issue you had and am sorry for the inconvenience. I am glad that you figure out what features cause the issue. Let me tell you what is happening behind the scene.
This Form Rendering issue usually happens due to minifying one of the Core files of the MetForm plugin. If you have applied Minification rules to all the Static Files(CSS, JS) of your site, then you may face this issue.
But, there is always a solution. You can use any type of optimization plugin you want. But, to prevent this type of rendering issue, You can exclude the MetForm plugin from being Minified by the Optimization plugin you are using. If you are not seeing any options to exclude the MetForm plugin, then there can be an option to exclude specific files. You can add this File to that Exclusion List of the Optimization plugin. I hope that will solve the issue.
Let me know if that helps or if you need any further assistance in this matter. I will be happy to help you.
Best Regards,
Prosenjit