Hi,
My account shows that I am member of Exercism insiders program (since 3rd Feb 2024) but when I try turning the dark-mode switch on at the top it flips back to normal mode automatically. I am not sure if this is some kind of bug. Also, I want to mention that I have not done any donation yet (this batch was awarded to me).
I sent few emails earlier to hello@exercism.org regarding the same issue.