Hi Eric,
I don’t think you can change the symbols in EVFR. I think it’s programmed so that OGN-R ground stations show up as an antenna mast ( inverted Y ) but I think your ground station maybe is still a standard PAW traffic unit? That will show up as an aircraft! You could try asking Rob Weijers the question via the PocketFMS EVFR forum.
With Sky Demon, even the OGN stations show as aircraft as was highlighted on another thread; not sure about other Nav Apps?