It appears you only set the border color but not the border width or the border type. SO check the options of the plugins you are using and eventually ask the plugin developer how to use their tool.
But it appears you are using a table to create your box, and this is a bad idea as table are not very responsive and will likely cause trouble on mobile.
You can also just switch your content editor to text and use HTML like below
<div style=”background-color:grey;border:2px solid red;”>Your content for the box </div>