Having flown about 10 flights so far, half of the time the system shows obvious delay, I have to turn off the goggle and then on again to be back to normal.

The delay includes all system messages like motors arming, stopping, etc. also when I flip the c2 button to tilt the camera angle, it delays at least 3 seconds. And there is no response when pressing recording button.

If I don't reboot the goggles, I can still arm motors, fly and safely land the drone but the home point is not updated, no system messages about arming / disarming motors, battery remaining gauge is not updated.

I am not sure if it only happens to me. DJI, any updates to fix this ?

Yes, have experienced the same.