It looks like there’s something wrong with the airport night lighting, at least on Xbox, after Sim Update 6. Distant lights continuously flicker, especially runway and taxi lights, but also overhead lamps and smaller buildings in cities.
It’s probably not fully visible on the videos as the captures are too dark, but it’s quite distracting in real. It looks as if resolution has been lowered, or the upscaler doesn’t work properly on lights, hence the excess amount of flicker. I noticed the same on terrain objects like fences while taxiing.
It looks pretty bad on approach as well, runway lights just flicker and it’s distracting.
This video perhaps demonstrates it better. Watch the runway as the aircraft approaches and lands (best viewed in full screen mode): Approaching runway at night
Edit: I removed the Xbox tag from the title as the issue is confirmed to occur on PC as well.