Alt tags not displaying on homepage

Hi there,
The alt tags to all the images on my homepage are not displaying and its affecting my SEO. The Developers at AIOSEO have had a close look at the issue and determined the problem is with the theme (High End). They have also provided a screencast of the issue for you to see the problem. Below is part of an email to me from AIOSEO with details,
Hi Jervaiz,
I checked in your website for the image alt text issue, and found the issue coming from your theme “Highend”.

If you notice the class name woo-category-wrap under the hb-woo-image-wrap class, by simply noticing the initials of the classnames you can get a clear idea that these classnames are coming from your theme and your theme provider can provide you further assistance regarding how you can add alt text to those.

AIOSEO is perfectly generating alt texts for your WooCommerce images and thumbnails and for other images too.

I’ve recorded a detailed screencast for you so that you can understand the situation clearly: https://a.supportally.com/v/NewmbJ

Can you please take a look and let me know how to remedy this, thank you.