Driving in box junction, new driver.Watch
That isn't a no right turn sign, a no right turn sign is a legal standard and it's a right turn arrow against a white background with a red circle and red line across it. It is also on the incorrect side of the traffic light to apply to right turns. This looks more like a green light to turn left except for busses, which when not illuminated would be completely black
That doesn't mean people can't turn right from this side though, I expect it's just denoting that busses are exempt from red light conditions and it's probably only used at certain times of day. There's no illuminated sign for no right turning
When I say the other side of the road, I'm referring to the signal on the far side of the junction but still facing where the OP was, not the opposite stream of traffic.
There's an example of one here- I have never seen a part time no right turn before in my life.