According to https://drafts.csswg.org/cssom/#resolved-value-special-case-property-like-top
If the property applies to a positioned element [...]. Otherwise the resolved value is the computed value.
An element with position: static is not positioned, so the resolved value is the computed value.
According to https://drafts.csswg.org/css-position-3/#box-offsets-trbl,
Computed value: For position: static, auto.
So I would expect this:
element.style.top = "10px";
getComputedStyle(element).top; // "auto"
However, all Firefox, Chromium and WebKit return "10px" instead.
Either CSSOM or CSS Position is wrong.