This is a one-tick signal right

Yeah

So in Java when it powers a sticky piston it won't retract it

That's because the redstone dust is powering the block the piston is next to. It's the same on java and bedrock

That circuit was broken on bedrock during 1.16

It's more reliable when the repeater comes before the piston because it guarantees that the piston won't get powered until the redstone dust is

I've actually been working on Minecraft computers all day and built like 5 of those