For a podcast consistently in that Goldilocks zone, I recommend Sleep with Me
I’ve been listening at bedtime for over a year and it’s one of the only thing that consistently helps me sleep. It’s not for everyone, but if it works for you it’s amazing.
Sure, essentially they are bedtime stories, crafted specifically to be interesting enough to distract you from intrusive thoughts that prevent you from falling asleep, but boring enough that it doesn’t stop you from falling asleep. It starts out with an intro that explains what the podcast is, and is different for each episode. Usually it is used to wind down for bed before the actual story starts. The point isn’t to put you to sleep, but to keep you company while you fall asleep, and at least for me his voice is the perfect monotone to put me right to bed.
It’s hard to fully describe the podcast, I would recommend trying it once, and seeing if it vibes with you. Sometimes I’ll skip the intro segment and jump straight into the story, and there is a plethora of different series and stuff to choose from, some are episode recaps of Star Trek episodes, to his own written stories like the multiplex, you’d have to look through the catalog.