I'm wondering where you got the url address. When i go on https://libreelec.tv/downloads/raspberry/ the download link for the rpi4 image is https://releases.libreelec.tv/LibreELEC-RPi4.arm-10.0.1.img.gz
Oh.. i just noticed, that https://releases.libreelec.tv/ redirects to http://releases.libreelec.tv/. Is there any problem with the ssl certificate?
the link is changing while clicking on the download button