Hello @LeXXik,
Thank you for your time and explanation! However, even when I deactivate all updates, I still don’t have a smooth movement of the cube with the test script.
As for the sensors, I just followed the advice in this post:
I deactivate everything and then this is how the cube is move on my laptop:
I’ve created a new project with only a camera in it. I also see an FPS drop with lower-end device setting (slows down CPU), even though there is nothing to render. Perhaps, @yaustar could look into it.
When is a device lower-end?
Its just a simple setting in Chrome dev tools (upper right corner):
The setting is relative to your computer, and it just artificially slows down your CPU by 4 or 6 times. Not really matches the real devices, but approximates the performance.
Is the FPS drop consistent up to 20-30 secs? There’s some startup stuff that takes a bit at the very beginning.
But if that were the cause then I should have a lower end device and I don’t think that’s the case.
Ah, you are right, it was only at the beginning. You can ignore it.
Well, the cube moves fine on my laptop, so I thought you were using a low-end device setting. Does your browser have hardware acceleration enabled?
(PS, sorry, seems I didn’t mute the background music…)
Where can I check the hardware acceleration?
On my mobile (iPhone X) it’s working fine to.
But my orginal build of the game that you played already is working also fine on my laptop.
So I realy don’t know where to search.
Maybe I have to start a new project again, but I like to know what causes the problem…
What resolution is your monitor or laptop display?
1920x1080 and 144hz
To be sure I removed the player entity and the player script, and the problem in this project is still there.
It’s very possible that the browser at full screen can’t render at 144Hz so it looks choppy to you. 
Try making the browser window smaller (like a quarter of the size) and see if the issue persists.
If it still does, do a performance recording in the Devtools and save the file so that we can download and take a look.
It seems that with making the screen smaller everything runs smoothly indeed! That explains why it works smoothly on my mobile.
But what I don’t understand is that I only have this problem in this project. I have another player movement project in which the player also moves smoothly on full screen…
If you are using Chrome browser, go to Settings > scroll down > Advanced > scroll down > System > Check “Use hardware acceleration when available”
This is enabled.
I put everything from the problem project in a older project and everything works fine,
so I’m going to continue in that project.
Probably the cause is not going to be identified, so I am still worried about future projects.
I have a fork of the project but on my laptop it looks ‘fine’ and I don’t have a 144Hz display to test with. I take a deeper dive if I can
I just saw in someone else’s project that the problem is also when using renderLine to a moving object. The line follows the object very stuttering, unless I make my screen smaller. I hope that there will be a solution soon.