I noticed 2 Class 101 sets and have noticed others at other times, didn’t have a their respective passenger lights on when in active service at Darlington noticed sometime after 18:00 whilst operating a Class 31 freight to Darlington Xbox Series X
They've been off ever since it came out in 2019. I have a vague memory of it being fixed, possibly when tsw2 was launched but don't take my word for it. It's now back to the way it was originally with all AI trains running around in darkness. I doubt it's very high on their list of priorities to put it right.