Triggering a popover from an element inside a scrolling container causes the popover to be static when scrolling inside parent - this is because the overlay is position relative to the window & not to the scrolling container.
Though it might be a good idea to provide a class string/id instead of an HtmlElement because parent elements may be many levels up in the component hierarchy and awkward to pass through to the popover.load
e.g.
<app-wrapper>
<some-component class="scrolling-container">
<and-another>
<popover-stuff></popover-stuff>
</and-another>
</some-component>
</app-wrapper>
this.popover.load({
injectOverlayInside: "scrolling-container"
})
Passing a class/id avoids drilling the element through multiple components.
Tried to fix this myself but the underlying CDK is closed-source.