Accent placement or size.

Style/General...Articulations?

The default position is below the chord, and even though that takes a little more vertical space, I think it would have been preferable. In a score for multiple instruments I might stoop to flipping the accent above in order to avoid the staff below, but in the part I' definitely keep it in the correct location or it would be too easy for a performer to miss.

EDIT: On closer examination I see that you may be using multiple voices here? That's one reason why attaching actual scores beats attaching pictures. Anyhow, in that case, the default is indeed stem as discussed elsewhere. Kind of unfortunate when stemless notes and ledger lines are involved, to be sure. I don't see that Elaine Gould specifically discussed this particular combination of factors in her book "Behind Bars", so I don't have any particularly authoritative source to reference.