Hostile mobs spawning in lit areas as high as light level 13

Render Distance: 5-8 (Changing constantly, depending on what I'm doing.)

Simulation Distance: 4

Dealing with some phantoms when I caught a glimpse of what I call a "freak spawn." AFAIK, Zombie Sieges are Java only, I believe.

Note the Zombies' brightness & the group dispersing in the video (both indicators of a fresh spawn).

 

Strays for some reason cannot jump out of any full block Top Snow/Snow Layer they spawned in. Whenever I catch the event, I will post images/videos of Strays being stuck in the snow as that is substantial evidence of this bug.

 

Edit, Tue. July 11, 2023: It happens quite rarely (about once every night, if you're lucky to witness it), so I can't guarantee this method of explaining would suffice, but here goes.

Steps to Reproduce:

1. Be in a roofed area (i.e. caves, buildings, etc.) or wait until it's night.
2. Stand in the center of about a 30 block radius of lit area.
3. Wait for mobs to spawn, which should happen almost immediately.

Expected Results: Mobs should spawn according to the Caves & Cliffs rules. Passive mobs under skylight  with lit grass blocks, while hostiles should spawn only in light level ZERO.

Observed Results: Hostile mobs can sometimes spawn as close as 1-2 blocks away from light sources, rendering light sources virtually pointless (check the videos/images please). 

Could be a Switch only bug. So please have someone with one test this. Thanks in advance.