Hi,

The web developers said with you it's a theme issue - the guys seem doesn't understand or know about "Lazyload CSS" and "Lazyload JS" - you can copy my reply and send it to them.

First, our Critical CSS tool will scan and create all needed CSS for your pages and load it only when users visit your website.

All CSS files and JS files will be delayed to load until the user interaction with your website like scroll down, click.. That means, in the first load, the site will bring your readers the best load. As you can see instead of waiting for a white screen after access to a website you don't need to see it if you're using our theme.

About the images loading time, let me show you how it is slow.

First, we need to use lazy load images to delay the loads for images on your websites. The images will load when the user scrolls to them.

Let imagine, currently, your site has 9 images loading on the homepage, if we don't delay images to load, the browsers need to wait for 9 images loaded before appears your site interface for readers - it will increase the loading time.

And one IMPORTANT point here - let check the images you're using - for example this image - It has the size: 8192 x 5464 pixel and weight 2.4MB ( you can download this image to your computer and see ) - that's a very very huge size and needs much time to load. All your other images have the same size as that and in total, you need to load about 20MB for images only.  Let ask yourself, how much time do you need to wait to download something that has a size 20MB?

A normal .JPG image just has a size of about 30KB - smaller 80 times with 2.4MB.

So, the solution for you now: Optimize your image sizes & image weight

To optimize image size, the theme already does that for you if you upload a new image. But, it seems it's images from your old theme, so you need to install the plugin Regenerate Thumbnails and go to Tools > Regenerate Thumbnails > and click on the button to regenerate thumbnails for all images on your website.

To optimize images weight, you can use a plugin like this plugin:

https://wordpress.org/plugins/ewww-image-optimizer/

When you have done all, check it again. And I think the web developers you've asked before even don't know what's your site problem - their job is just to blame the theme.

Best Regards,

PenciDesign