Piston / sticky piston head does not visually appear for a few frames after being powered from the side it is facing

is that a bug? or just a feature

if it becomes a bug, that is too bad, I'm worried now.

Wasn't able to reproduce this. If possible, can you please attach a video showcasing the bug?

I also cannot reproduce this. Please provide clear steps to reproduce the issue, and as BugTracker also stated, a video would be helpful.

Can reproduce the issue, but it only happens for a brief moment. Also, you need a block above the redstone torch for it to work.

Thanks for the clarification. I also found MC-265372 which seems very similar to this issue:

In the video, we find out that in some frames the piston head isn't shown while the redstone torch is broken not as an block(like a dropping block), it's not the reason that redstone torch block blocked the piston head. The piston is unshown because of itself and no blocks block it! Not reasons!

and

Plus for my comment, the

shown also

So, that makes time to load up the piston, whether we use obsidian or the redstone block

few frames! (lol)

Confirmed in 1.21.3