Here are some I enjoy. All have a good voice, not overly expressively and no sudden change in background tracks. No sudden screaming/explosions/anything that will wake you.
John Michael Godier Science/Speculative Scifi, Low Soothing voice, even has a sleep playlist.
Issac Arthur Sci-Fi, Calm voice, Good background track, Long Videos
Forgotten Weapons Firearms, Historical and Mechanical overviews and indepth discussions. I recommend you skip the shooting range stuff if you're trying to sleep.
EmpLemon is always great, Alt Shift X has some fun ones on sci fi too, but Id guess u know both already, still might as well mention them on the low chance u dont