Polar bears only spawn in light levels > 11. This contradicts the vanilla behavior pack, which says they should spawn in light levels 7-15. It makes polar bear spawns more rare than they should be, and more difficult to collect or farm.

Steps to reproduce

1. Load the test world, MCPE-105220 Polar Bear Test.mcworld. It contains an ice spawn platform in a void frozen ocean world. The platform is divided into two sides. Leaves above the ice reduce the sky light level to 11 on the west side and 12 on the east side. Command blocks replace ice where polar bears spawn with purple concrete and then kill everything to keep the mob caps empty.
2. Stay on the grass block and wait for a long time.

Expected results

Polar bears spawn on both sides of the ice platform.

Actual results

Polar bears only spawn on the east side of the ice platform, where the light level is 12. They do not spawn on the west side, where the light level is 11.