Currently, if you attempt to Sort by Versions within the backlog of a Scrum project, there are inconsistencies shown when the child issue's fix versions are different from the parent Epic fix version.

For example, a child fix version is "Version A", and the parent Epic fix version is "Version B". If you select "Version A" within the version panel of the scrum backlog, the child issue shows appropriately on the far right hand side. However, if you expand the Epic panel as well, the parent Epic is also not greyed out/is shown as "highlighted" despite not matching the fix version filter of "Version A", since the parent has the fix Version B instead. However, if you decide to filter by the version of the parent instead and select "Version B", none of the child issues from Version A display, despite them being related to the parent issue in a same manner you would expect them to be displayed from the inverse scenario.

This inconsistency in display seems to contradict the purpose of filters to only show issues within a certain version if an Epic for a different version shows up only because it's the parent Epic to the child issues, regardless of what version that parent Epic is part of. The Epic should only appear as highlighted/not greyed out if the version selected is the one that matches the parent, assuming filtering order takes precedence "reading order" of left to right.