My answer to this is definitely influenced by the fact that I deal with chronic fatigue, but I have a similar experience to you: Reading on my Kindle makes me pass out!

Usually if I'm reading elsewhere in the house, physical or ebook, I'm all good. I can stay up far too late, despite my eyeballs suffering from exhaustion, but only if I'm elsewhere in the house. But once I settle in for bed and start reading on my Kindle (especially if it's a reread or a cozier book), I'm out relatively quickly. Pretty sure my partner wakes up most days with my Kindle next to or under him.

On the rare occasion I can't sleep despite reading in bed, I either switch over to a lighthearted audiobook or a bedtime Podcast (like Nothing Much Happens).

I think reading in bed likely creates an association for me like bedtime = reading, then sleep. Plus, reading really soothes my anxiety, which helps me sleep.