Thought he was played as an 8, didnt do much, got moved back to 10 and got back to his best?
Not entirely sure how transfermarkt defines its positions, but according to this he was AM the vast majority of games:
These are the detailed performance data of Nottingham Forest player Morgan Gibbs-White. The website contains a statistic about the performance data of the player.
www.transfermarkt.co.uk
LM x 2 and LW x2
And these guys say:
See all the career stats for each position Morgan Gibbs-White has played in, along with his rating for each position and preferred foot.
www.footballcritic.com
edit, that pasted in fine but did not post fine
AM - 37 apps
LM - 4
ST - 3
CM - 2
AM(right) -2
AM(left)1
Midfield(right)-1
(last 50 games)