I changed my username, now when I try to access a server, it says, "not authenticated with minecraft.net"
Comments 3
Log in and out of the launcher. If you're still having the issue after that please visit community support.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Mojang Support – ✍️ Feedback and Suggestions – 📖 Game Wiki
This seems like a technical support question. I recommend heading to the Minecraft Community Support discord server, where volunteers can assist you.