I am managing a website for Sign Language users, and we are trying to make the website more accessible by including more Sign Language. The website is https://deaf.org.nz
We have started using GIFs as Featured Images to provide a snippet of what the video post includes. Unfortunately, GIFs are huge and this impacts the website performance. I have tried to convert a GIF to a WebM file format and replace the GIF with the WebM as a Featured Image, but this does not work. The WebM file is uploaded to the Media Manager. It plays fine in the Media Manager.
Not sure if this is an issue with GeneratePress or WordPress. I have turned off the SG Optimizer Plugin.