I have noticed an increase in mob spawning rates and volume since 1.16. At first i thought that this was a good thing, however I can't get the mobs to stop spawning. Putting torches, glowstone, etc does not seem to stop hostiles from spawning all that much. They seem to spawn where there is a relatively low light level in an area instead of below a set light level. For example: I have had spiders, skeletons, zombies, and most annoyingly, creepers spawn inside my house. I have lanterns, glowstone, and torches all through my house. I started to put more as they continue to spawn, but it does not stop them. Maybe I am just lacking in knowledge of the game, but it really seems like this shouldn't happen. (I could not find this issue anywhere else in the forums so I apologize if it has already been covered.)

Note: In the screenshots included, I also have glowstone and torches underneath the slabs in the floor.