Steps to reproduce:

1. Place down a repeating command block with the command: summon ender_crystal ~ ~1 ~
2. Activate the command block and wait for a few seconds
3. Go up to the command block, look at it's edge:
   
4. Sneak

Observed result:
The animation stops playing and the end crystals display as if they are a block.

Expected result:
The animation continues playing like usual.