The stats on the squad summary screen don't match the stats on the individual player screen. The CM and CG should be the total matches and goals (for all seasons) for that player for your club only. See example below.
The total of club matches is wrong.
...and comparing the squad summary with totals for all squad players:
Note S. Dowridge - an academy player recruited on Day 2 this season. He's only played one full match, and made 1 uncredited sub appearance (less than 20 minutes played) yet he has 5 appearances in the summary - he can't have played for anyone else, and I don't play friendlies. Notice also that the number of goals scored matches perfectly with my records.
Conclusion: Something has screwed with the CM on the Squad Summary screen - don't believe it.
EDIT: I have a theory that the CM column may also be adding in occasions where the player concerned was an unused sub - I can say for certainty that it does in the case of the players 14/15/16/17 above, all four recruited this season... Just need to get enough screencaps together as proof for their Lordships at Nordeus development...