Hello @Zorrototo, this issue is already being tracked at #6064. Closing as a duplicate.
The problem is not the 0 bytes update, but THE RE-DISTRIBUTABLE (directX, vcredist, and so on...) of my proton game downloading every time.
I had the issue with the shader pre caching downloading again every time I was starting Steam, but I disable shader pre caching, and it solved this issue, this is another issue.
If I don't boot on Windows and start my Steam (like if I only reboot on Linux), I don't have to download redistributable every time I start Steam, it is only after booting and logging into Steam on Windows then rebooting and going back to Linux that this issue occurs.
Are you using the same Steam library with both OSes?
If that's the case, https://github.com/ValveSoftware/steam-for-linux/blob/master/RelNotes.md#installation notes that this is not supported and can lead to unexpected quirks.
No, This is what I tried first time I installed Linux and noticed the problem back then. I have everything separated, my Linux SSD only has Linux Steam and library, and my Windows Steam is on the Windows system disk alone. Nothing shared between the two systems.
I don't even mount my Windows SSD on Linux.
Today I played on my Windows system, then after rebooting to Windows, Steam didn't download anything on the Linux Steam. Did something got fixed?
Nothing extracted yet.
Your system information:
Please describe your issue in as much detail as possible:
After using my Steam account on Windows, when I reboot to my Linux disk and start Steam, Steam thinks all or most of all my Proton games require an update. If I force all these updates manually they instantly end (0 bytes downloads), but the real issue here is that it will re-download most/all the redistributable (Common Steamworks things) for my Proton games, without any other reason than I rebooted previously on Windows and logged into my account. This is always the case when I reboot on Windows and start Steam, then reboot again on Linux this always happen.
Steps for reproducing this issue: