Website layout readjusts/bugs/shifts out after a few minutes

Hi everyone,

Best wishes for the new year!

I have a problem with my website/design phase. After being a few minutes on the page, my website bugs out (not sure if this is the correct terminology). I am not sure what the problem is, but maybe you might know the problem and could help me out.

What it looks like before the bug/readjustment:

. I want it to always look like this.

This is what it looks like after a few minutes on the page/ what it turns into after the bug/readjustment:

Thank you in advance!

Probably you need to add correct dimensions to your image or div(or what you use to contain the image. Width and height, if you use Safari, I would fill all fields.