See Repro steps. Faces are selectable when either Allow Translucent Selection or Draw Brush Polys is enabled, but not when they are both enabled.
Add any type of Volume to Scene (eg Exclusion Volume)
Change active EdMode to Geometry Editing mode
Enable Allow Translucent Selection and Previewing/Draw Brush Polys options under Settings drop-down in main Toolbar
Can select Volume, but can't select any of it's faces
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-93851 in the post.