On the latest version of Minecraft Bedrock, there is a bug that affects leaves. When pushing any leaf type with a piston (including azalea), to they will immediately disappear. This is also the case with sticky pistons. When you attempt to pull a leaf with a sticky piston, nothing will happen (similarly to trying to pull obsidian or bedrock). This works with all orientations of piston as well.

(Here is video link, was too big to upload)