Another possibility is shader cache updates.
I had a small update for 7D2D pushed down yesterday, but when I check both the file dates and the update date, it shows the last update was 12/21/2021 for the main game and 12/27/2021 when I had it download me a new copy of traders.xml after I messed it up accidently.
Try going into Steam -> Settings and at the bottom is Shader Pre-Caching. Unclick everything and you should stop seeing those micro-updates happening. However, it does note at the top that allowing Steam to do this makes Vulcan and OpenGL games load faster and have more stable framerate while playing (that is what it says, I am not validating their statement).
As an experiment, I unclicked it so it cleared everything and then re-clicked it. Steam then downloaded updates to at least 6 of my games right away.