I seem to have found the culprit. There was a post that I looked at yesterday, regarding fixing the browser/Chrome integration while using WSL2: How to Run Antigravity Browser Automation on WSL2 · GitHub
Reverting every change I made from these instructions, the port forwarding and the .zshrc/.bashrc snippet allowed the language server to setup properly. I hope that agy . will seamlessly work (without needing to follow this guide Antigravity CLI (agy) on WSL: broken launcher & missing scripts (manual repair report ) and the browser will work soon in WSL2, otherwise there will be many more cases like this.