After doing some digging with my browsers built in developer tools it looks like you are using Theme Neve from ThemeIsle. I think this is a problem with your theme meaning you’ll need to ask in their support community: https://wordpress.org/support/theme/neve/.
I can see also you are using the SG Optimizer plugin there could be a conflict with the settings of the plugin and your theme/hosting. This plugin will only work correctly if you are using SiteGround as your website hosting provider. Generally, I do not use the plugin though even for sites that are hosting on SiteGround I have found that it does not improve results if you are using the built in caching options server side the plugin does not really help much except to give you a “development mode” button on the wordpress side.
Hope this info helps get you headed in the right direction.
@binarywc Thank you very much for the response, I really appreciate it. Probably should’ve included that in OP. I’ll try my luck over there too. Wasn’t aware that the SG Optimizer doesn’t provide much in terms of results so I’ll do some tweaking there too.