How to stop Cloudflare converting my files to AVIFc

Cloudflare is automatically converting some of my product images to AVIF files (they should be jpeg!). The AVIF cannot be viewed on the Microsoft Edge browser, so the product images on Edge appear blank. How can I stop cloudflare from automatically converting my product images into AVIF?

It was never doing this before and has just started. It’s creating an error inside Klaviyo because the product images are syncing across as AVIF files and won’t display their either.