Resize designer canva with mouse sometimes not working

I don’t know why sometimes i can resize the designer canvas with the mouse and sometimes no you can see what i mean in these two video

working (the website is not resizing because i have the fluid responsive)
https://www.loom.com/share/b069967f2e6049e3a5e1100c8b60508c

not working (after refresh)
https://www.loom.com/share/2ab258146ab643cd8bb651645b04caf8