After about 1-2 minutes, I would get disconnected from Valheim. I was fine the entire day, but now that blinking PC icon in the top left would go off, and within 30 seconds I'd be Disconnected.
My Solution: Restart my router
The rest of my internet was fine. But, there is a Player.log locally on your system and when the disconnect happened, it reported "ZRpc timeout detected". This timeout is 30 seconds, and it essentially means the connection from you to the server is poor. I was playing fine for days, then out of nowhere I was constantly getting DC'd. No patch update, nothing.
So, I'm posting here on Reddit because it's a top result on Google and I wanted to share my solution. For instance, /u/VHD_ said in the
Other suggestions from online that didn't work for me:
Turning the render distance down
Run the valheim.exe as Administrator and not through steam
Restart PC, restart Steam
Didn't try: Moving the server location