Go to Preferences > General and check 'Yes' on 'Allow iframes on html fields'
For some reasons Prestashop has disabled this by default theme iframes, objects, embed etc... for security reason.
Hope above info helps.
The Product name is causing the issue. Some time you have two lines and some time you have three lines and thus the product box is of different sizes. There is two way to handle this. Either put the name in fix number of lines or put height in name or put the height for the whole product box.