Take a look at this. It's almost like ALS's skydome has got itself a little confused about the time, causing it to paint this out of position colour range on the skydome. If we switch the time to 17:00 local, this artefact blends in:
This also occurs at night time in the opposite way:
I was travelling:
At 1151kts GS
On 54700ft
200-400nm south-east of St. Petersburg, heading in a south-west direction.
Interestingly, the artefact disapeared after switching back to an outside view after being in the cockpit view for ~5 minutes.
See my PC information by clicking on my username.