Alignment selection boxes

Sounds a bit like the combination of the default styling of the elements from my plugin is not working for your theme. The only solution is to inspect the element (right click ? Inspect) and find the CSS rule that is causing it. Then overwrite this rule in your Additional CSS for the theme. But this requires some CSS knowledge to fix it properly.

Thanks for your reply.
For some reason setting an additional CSS rule with the following worked out for me:

input.bonus {
width: 5%;
}

This will also change the width of text inputs. If you are not using those, then that is fine. If you are, then I suggest making it more specific, e.g. like this:

input:where([type="checkbox"], [type="radio"]).bonus { ... }