I tried to download the installer from the website but when I’m redirected to download.documentfoundation.org I got a timeout error. isitdownrightnow also display this subdomain as down, is there a temporary problem?
The correct download site is https://www.libreoffice.org/download/download/, and the site is up (just tested).
Yeah it works now, but once you click on dowload it does give you a dowload link on the subdomain, for example https://download.documentfoundation.org/libreoffice/stable/7.2.3/win/x86_64/LibreOffice_7.2.3_Win_x64.msi
That link though redirects to a near mirror (picked of a list of mirrors), you can see the list with manually pick a mirror on the interim page or when clicking Info under the Download button on the download page. So maybe the mirror that is picked for your location is down, just choose another one from the list.