Don't know if this is an data issue, but the values of some players are a bit weird.
Besides Bella-Kotchap is Ismael Saibari with 36 milion euros the most valuable PSV player. More than Lang (21m), Tezet (21m), Veerman (17m, Teze more than Veerman?)) and Bakayoko (who is only 8,8m).
At Ajax Kenneth Taylor has an value of 179m, Hato 169m and Rensch 114m. I think it's quite unbeleivable that Taylor is 158m more worth than a player like Lang.