MC 1.21.1 / Fabric 0.15.3

architectury-9.1.12-fabric.jar
cloth-config-11.1.118-fabric.jar
fabric-api-0.91.0+1.20.1.jar
jei-1.20.1-fabric-15.2.0.27.jar
modmenu-7.2.2.jar
Galosphere-1.20.1-1.4.1-Fabric.jar
Soulbound-Fabric-0.6+1.20.1.jar

latest.log

Galosphere-1.20.1-1.3.1-Fabric.jar
Work fine -
latest.log

I've had the same problem. It seems to be a mixin conflict on "InventoryMixin" since both mods add keeping items on death through enchantments and smithing templates.

Update soulbound-fabric-1.0.0+1.20.1 fix this problem