Hello Mahaona,
I have checked your source page, and I saw that you are using some untested plugins, like Jetpack module. Try to disable all of them, leave just Visual Composer to be active, clear all your caches and check the results. It seems to be js errors which break the ajax filter feature.
Thanks for your understanding!
Hello Mahaona,
I have inspected your website and I did not saw any problems with your images. So, please notice that you are using the Block 10 at the very bottom of your homepage and this type of block do not display the featured images, as you can see here -> https://www.screencast.com/t/XGgZnJW13n9 Where is the problem?
Thanks for your understanding!
Hello Mahaona,
Please ensure that you are using the latest version of the theme and also, if you are using some untested plugins, please try to disable all of them, leave just Visual Composer to active, clear all your caches and install only the plugins that come bundled with the theme packet and rule out any conflicting plugins. The ajax filters are fully tested and work will all of our blocks of the theme and should work without any problems. If the problem is still there, try to make a new clean install from scratch via FTP way and check the results.
Hope this helps and let us know how it goes!
Thanks for your understanding!