@Whistle So I found out how and where the Issue came from. Updating Factorization should fix the Issue properly. Asie is maintaining it by now instead of Neptunepink.
https://asie.pl/files/mods/Factorization/
This fix will be in the install Instructions of GT6 too, so the hack that I did to “fix” the Issue for you is not gonna be included, since updating Factorization fixes it amoung many other Issues. 