it seems like the latest update for the J League there has been a complete physical nerf to the majority of J League players, who now have average pace/stamina of 9-11 maximum (first noticed this as nearly all fullbacks/wingbacks are shown as preferred inverted fullbacks due to their slow pace
This is across a ton of players. If you edit them up, their CA jumps considerably - it almost feels like the players have been min/maxed like the turkish league was