Also did a test race on Nordschleife yesterday, I was on a TCR mod car (Seat Leon), once in a while I've had again the flickerings.
As there are porsche cup cars on the field some of them were there when the test race was running, I think it's not the issue with driving the porsche cup itself, but whenever any porsche cup cars are on the track and cross s/f line. at least the flickerings appeared shortly on after the other and only for a few seconds, so I'm guessing whenever those cars drove within a few seconds to each other. I couldn't verify if indeed these were the causing cars or if it's already a bigger problem now (meaning other cars causing it now too, maybe).
we had the following cars / classes on track: gt3, gt4 (alpine + porsche cayman), porsche cup, tcr (mod), historic dtm, renault clio cup.
this event currently uses the 1130 release candidate branch. but at least with only porsche cups i could see this issue also on 1128 live build.
and to mention: never had this issue before until I've bought the porsche cup, just recently, for this event.
gonna be an interesting 24h event if this happens for every lap while driving
