[2021] No steam overlay in-game

Hello @Avlantia, could you verify if the executable GameOverlayUI.exe within your Steam folder has the “Run this program as an administrator” option toggled?

You can also try to temporarily close down all software running in the background that could interfere with both the game and the overlay, such as antivirus, firewall, fraps, GPU/Motherboard/Gaming peripheral applications, etc.