I'm using 126.96.36.199 on Linux Mint, which uses the Debian packager. LO told me there was an update available and presented the Check for Updates window. When I clicked Download... it took me to the downloads page with "Linux (64-bit) (rpm)" selected, when it should be "Linux (64-bit) (deb)" in my case.
Changing the selection from the operating system pull-down menu is trivial, of course. But other people may not be as observant and accidentally download the wrong format.
Selecting stuff from the menu shows that the page already supports a "type" parameter, the Download... button from the Check for Updates window just isn't providing it.
Generally: Linux distribution remove the update functionality from their packages due to the fact they have methods through their respective package manager to assure upgrades of LibreOffice.
That's the case with distribution releases of LibreOffice in openSUSE (Leap 15.2 in my case), Ubuntu (20.04 on my case) and Mint (20.1 in my case). Hence it is not clear, why you have the update functionality, if using the distribution specific packages.
From my perspective the only explanation for having the "Check for Updates" functionality would be: You download your LibreOffice version from libreoffice.org.
Could you comment on this?
You are correct. The LO package provided by my Linux distribution's package manager was too old for me, so I had downloaded a later version from the LO downloads page and installed that sometime in the past. Then yesterday, I went to update that using the Check for Updates function.
Since downloading Linux packages from the web is clearly a supported use case, I think the updates manager should be able to automatically select the correct package set for me when I do that.
I stepped back to 188.8.131.52 and tried it. It doesn't pass the type parameter in the URL, but the server seems to be consistently selecting Debian anyway. I will guess that it is looking at the User-Agent to determine that. I'm not sure why it wasn't working before. I guess I should mark this as WFM.