I don’t think it is glitched, people are still getting the trophy. You just need to make sure every planet is 100% explored - if you find one that is below 100%, then you can use the map to find the area and fully search it
So what if he doesn't know? No need for a response like that.
Might be worth emailing the studio or tweeting them if it's an issue, i can't see anything else online stating people reporting a graphics downgrade