Desktop UI: Scrolling doesn't work correctly

On my activity power page, I noticed that it filled up more than the whole screen, but scrolling didn’t work. Tried moving to a different monitor (different dimensions), still didn’t scroll.

Looking at the devtools, the culprit is:

html.v-overlay-scroll-blocked {
    position: fixed;
}

The problem as shown here:

Disabling position: fixed with the correct behaviour:

Well, I see this CSS style has crept back in again, and once again broken scrolling on desktop… I know, scrollbars are considered “ugly”, but I’d rather have usability than “pretty”.

/cc @eva