For issue 1, if you haven’t cleared browser cache and cookies, would recommend doing so as it could be browser related. I believe there are some updates rolling out so if you are doing that already, hopefully that will help.
Curious what you mean about the second thing? I usually tend to use the alignment for elements.
If the elements are supposed to be “grouped together”, I would recommend using stacks or placing the elements in a container .
The third one could be if you have the created on Editor X banner on your site, that does account for the breakpoint size. I think it’s about 100 pixels so you could use the calculation to account for it. Don’t use iOS on the normal but I think they don’t account for the address bar when it’s visible.