Sticky Piston Randomly Fails to Pull Back 12 blocks

Hello,

I found a bug where a sticky piston wasn't pulling back a certain patch of 12 blocks at inconsistent moments (I couldn't see what variables were consistent in my testing). I double checked it was 12 blocks and even rebuilt my redstone machine in different configurations, but it would still occur. Although the 12 blocks I'll show were the most commonly affected, I had the bottom 12 also not work a couple times. It's also worth noting this didn't happen yesterday.

https://youtu.be/t_3WEETN_UU 

https://youtu.be/yV7I81pNYUA