Azalea leaves and flowering azalea leaves broken with Silk Touch do not stack with those broken without Silk Touch

Summary:
Azalea leaves and flowering azalea leaves broken with Silk Touch do not stack with those that were not broken with Silk Touch.

Steps to Reproduce:

1. Enchant a tool with Silk Touch
2. /give @s azalea_leaves 2
3. Place 1 azalea leaf
4. In Survival mode, break the azalea leaf with the Silk Touch tool

Observed Results:
The leaves don't stack.

Expected Results:
The leaves should stack.

Video:
Minecraft 2021-03-21 10-47-28.mp4