Hi, I'm new to the game and I've spent nearly all day trying to figure out some kinks in my UI

And even though I've searched everywhere I can't find anything relating to nameplates getting greyed out when people are too far.

As a healer I rely on this quite a lot so I know who I can heal and who I can't, but playing as a scholar in frontlines, my highest range spell is 30y but it's only greying out nameplates after 40-50y and I can't figure out why or how to change it.

Because of this, I end up trying to heal people who aren't in range because I think they are and I stand there like an idiot doing nothing.

Please help, this is super frustrating