"After redshirting his first season on campus, he started 11 games and played 587 snaps at right guard in 2018. Ross appeared in nine games at several positions along the line last season, seeing limited action except for a 56-snap outing against Appalachian State." Source: UNC 247Sports
Sounds like he got passed up on UNC's depth chart, transferred down to Marshall, then had a "personality conflict" with his O-Line coach, and now he's completely done playing football.
For anyone playing along at home, that means that since high school Ross has:
2017: Sat out a season
2018: Played as a P5 starter
2019: Played as a P5 backup
2020: Sat out a season
2021: Transferred down, quit football
If this is all happening with him giving maximum effort, then it sounds to me like he just doesn't like playing football. That's not as uncommon as you might think, burnout is a real thing. I hope the kid finds something else to be passionate about.