I have a Raspberry Pi 4B and over VNC, glxgears will only give me 1 FPS. But over regular HDMI cable to a screen, then glxgears works like a charm.
So is there any problem with the VNC server inside Raspberry Pi 4B or is it RealVNC that causing this issue?
The internet connection is fast and the Raspberry Pi have the latest Raspberry Pi 64-bit version of Bullseye.