Is it best to not assign a mod to P5 if you don't have the stats?

I just P5'd Corey Seager in the Event, but noticed that if I take off the gold mod, his stats are actually listed as being better than with the mod on. I'm still a couple hits short of being able to get any of the Diamond Mods, so it's just gold options right now.

Is it truly more advantageous to leave the gold mods off, or is this a visual glitch? SDS is kinda known for both at this point...