- Include a full URL where the bug appears.
https://github.com/miyataka/fcmpush/issues/12
or
some your own issue URL.
- Include a screenshot/gif
when disabled refined-github

when enabled refined-github


some version info


The selector needs to be made more specific
A better selector: .pinned-issue-item form svg.
There are other problems as well:
1 pinned issue with admin access:

The height difference is due to: https://github.com/sindresorhus/refined-github/blob/d4e158776dca70a0bd339872a5b005bf5382aceb/source/features/clean-pinned-issues.css#L30

Culprit:
That's the base of the feature, it can't be changed. Are there any floats that are pushing that down? Maybe the title just needs a max-width
Are there any floats that are pushing that down
You are right:

So basically change:
[action$='unpin'] svg {
margin-left: -10px;
margin-right: 10px !important;
}
to:
.pinned-issue-item form button {
float: unset !important;
margin-left: -10px;
margin-right: 2px !important;
}
Most helpful comment
https://github.com/sindresorhus/refined-github/blob/7500dc7ae236a21b26086ae163c45f32dbca83a9/source/features/clean-pinned-issues.css#L43-L46