Home page slide show didn’t work on https

I found there is a bug on the home page slide show, it displays no image when the site has “Force https://” setup.

With customised image, the slide show didn't work. Because the site has setup with "Forced https". Hence, the image under https:// didn't loaded.
<img src="https://www.nanomedia.com.au/wp-content/uploads/2023/10/1900-modern-digital-banner-city-background.jpg" alt="" class="slide-item-img d-block w-100">

With the default image, the slide show work well.
<img src="https://www.nanomedia.com.au/wp-content/themes/lightning/_g2/assets/images/top_image_2.jpg" alt="" class="slide-item-img d-block w-100">