It's not because of the update or bugs, it's due to existing optimization especially with Pagespeed (which probably hosting's optimization) plus incorrect file format.
To explain this further, please access the image URL in the secure note on both Chrome and Firefox. It's image URL from your site and you can pick that up using any browser developer's inspector.
You'll notice that the image renders okay on chrome, but it's not rendering on Firefox because the optimized image has
.webp extension. And if you'll check this, https://fileinfo.com/extension/webp. It's a file type or image type specifically made by Google and for Chrome.
WEBP files are typically created when a Chrome user downloads an image from the web browser by dragging and dropping it on the desktop or right-clicking the image and saving it in the WebP format. If you come across a WEBP file you can open it in the Chrome or Opera web browsers or with a graphics editor, such as Pixelmator, Image Magick, IrfanView, or XnView.
Please upload images with a proper format that works across different browsers.
Hope this helps.