moving instance downward with arrow key slowdown

[F3der1co]

Problem description

When moving an instance downward using the arrow keys the editor lags. Moving it to the right, left or up doesn't cause that issue.

Attach a .c3p

movingDownInstanceBar.zip

Steps to reproduce

0. make sure instance bar is visible (instance bar makes lag it worse, but it doesn't seem to be the real cause)
1. select an instance
2. hold the down arrow key

Observed result

editor lags

Expected result

editor stays smooth (like when pressing any of the other directions

More details

IMPORTANT: while in this case the problem gets worse when the instance bar is open, in my main project the problem also happens when the instance bar is closed.
It's so odd that it only happens with down bur normal mouse dragging or other arrow directions work smoothly. So to me it seems like down iterates through many instances, maybe all layouts.

Affected browsers/platforms:

First affected release:

System details

View details

PASTE HERE

[DiegoScirra]

I can't reproduce this in the example project. The four directions use the same code, so if anything is wrong, all of them should be doing the same thing.

Maybe a more complex project?

If anything could be slowing down is in the case of having a complex hierarchy (many levels deep) which in turn is a template and itself has a lot of replicas. Then moving some part of the template might be slow when it tries to update the corresponding part of all the replicas. That's just a guess though.

I though this might be related to #8067, but that one only affects relatively deep hierarchies.

[F3der1co]

There is no hierarchy in this repro.
here you can visually see the slowdown (its smooth in all direction except down), it also shows up in the chrome performance profiler. (the mouse movement is just me showing which direction I am going to press)
Really weird that it does not reproduce for you. I'll ask around or try on other devices to see if it only happens for me.

Downperf.mp4

[F3der1co]

It seems to only reproduce for me in chrom (I'm on 127.0.6533.120). Edge works fine.
I tried resetting chrome but it didn't fix it. I'll investigate further

[DiegoScirra]

Did you try resetting everything when you type chrome://flags/ in the address bar?

[F3der1co]

I reset chrome flags as well and still have this issue.
But I guess if it's just happens for me I understand that there isn't much you can do :/