Runway lights changing color and shape when getting closer

[abandoned account 171]

I have a weird issue with runway lights. When they get close to the a/c, they change color and/or shape. See screenshot:

http://fsfiles.org/flightsimshotsv2/image/Gmp5

 

It occurs on all runways all around the world that I've tried, stock and add-on sceneries.

 

This is P3D 3.3.5 and I have all the common addons like REX and the ORBX stuff.

Unfortunately I can't remember if this happened from day one without the addons.

I've tried any and all settings I could think, disabling/enabling sceneries, tried the orbx 3d lights configuration tool, and so on.

Switching runway lights within REX changes the lights as expected but the behaviour still remains.

 

Setting HDR lighting to off seem to make the center lights behave this way instead. On the above screenshot, it's set to on.

 

Any ideas why this happens?