How do I resolve this problem with the elements of my game?

Hello!

I have a serious problem with my game and I don't know how to fix it. I'm desesperated, because is urgent :|

I'm developing a runner game and I have created all the levels, but different elements (some obstacles) show up floating in the air instead of being on the surface. The strange thing is, when the website is reloaded, some of this elements are relocated in its correct positions and some not depending on the mobile device, SO, browser...

Is the server making the trouble or is it my Construct project in terms of not managing correctly the memory?

I let you the link of the project file here:

https://drive.google.com/file/d/1WV-Ktz8dtq_WNSC59aX63V0ajwFmdXle/view

And the website on which the project is uploaded is:

https://www.metamorfosischangecambio.com/

Thank you so much!