Redstone is very unconsistent in bedrock edition. Just add redstone order to it and it fix.

(I’m can’t find any report about this)

Step to reproduce

1.place two sticky piston face each other

2.use redstone dust to power it at the same times

3.do it again 

It will not lead you to the same results that cause redstoner to make thing slower than it should be

This also parity issues