In the 1.17.30 update the description says this: Monster Spawning. Monsters now only spawn in completedarkness
This change is being made to balance the player's ability to light up the new larger caves and make them safe from monster spawning. I do not know if it refers to the betas or the official ones but using the tinted glass does not affect the spawning of monsters and that is in complete darkness but does not generate mobs like in java.