An interesting finding: The issue only occurs with the A350-900 using the default cabin configuration. I have tested the following variants and they do NOT exhibit the problem: - A350-900 (No Cabin) - A350-900ULR (Default Cabin) - A350-900ULR (No Cabin) - A350-1000 (Default Cabin) - A350-1000 (No Cabin) So far, the problem appears to be exclusive to the A350-900 with the default cabin model installed. This makes me wonder if the issue could be related to the specific model variant or cabin package rather than the aircraft's lighting system itself. This may help narrow down the root cause, as the lighting issue seems to be tied to a specific aircraft variant rather than affecting the entire A350 product line.