I noticed an incompatibility with Earth2Java where Muddy Pigs cannot be spawned, logging "duplicate id" errors.

This seems to be caused by data trackers of this mod not being registered properly, relevant parts are here:
https://github.com/KxmischesDomi/MoreBannerFeatures/blob/af68487ceb9317479acc1c1258eb73a42f5049da/src/main/java/de/kxmischesdomi/morebannerfeatures/mixin/pig/PigEntityMixin.java#L144
https://github.com/KxmischesDomi/MoreBannerFeatures/blob/af68487ceb9317479acc1c1258eb73a42f5049da/src/main/java/de/kxmischesdomi/morebannerfeatures/mixin/boat/BoatEntityMixin.java#L129
https://github.com/KxmischesDomi/MoreBannerFeatures/blob/af68487ceb9317479acc1c1258eb73a42f5049da/src/main/java/de/kxmischesdomi/morebannerfeatures/mixin/strider/StriderEntityMixin.java#L119

Correcting the classes seems to fix the issue.

Thanks for reaching out, I'm gonna fix that tomorrow and upload a new verison on Curseforge ^^

Should be fixed with 163b9ec.
Guess I'm gonna update it today, not tomorrow

Fixed and uploaded: https://www.curseforge.com/minecraft/mc-mods/more-banner-features/files/3453480