When picking up a Minecart Contraption (by shiftt r-clicking with a wrench) hosted on a Thermal Locomotion Underwater Minecart it turns into a create:minecart_contraption. This means when placing it back down it has a regular minecart instead of an Underwater Minecart.
The assembled Contraption

Item data:
Item.of('create:minecart_contraption', {Contraption:{Blocks:{Palette:[{Properties:{axis:"x"},Name:"create:minecart_anchor"},{Properties:{axis:"y"},Name:"minecraft:oak_log"}],BlockList:[{Pos:0,State:0},{Pos:1,State:1}]},BoundsFront:[0.0,0.0,0.0,1.0,2.0,1.0],SubContraptions:[],BottomlessSupply:0,Actors:[],InitialOrientation:"EAST",Seats:[],Type:"mounted",Anchor:{X:75,Y:64,Z:-49},Superglue:[],Storage:[],Passengers:[],RotationMode:"ROTATE",FluidStorage:[],Stalled:0},display:{}})
The item

The contraption after placing it back down

There was nothing in the debug or latest logs.

Suggested fix is either not allowing modded carts to be used or having a new item, something like create:modded_minecart_contraption that stores the type of cart as well (or just merging that with the original create:minecart_contraption)

There is benefit other than aesthetics to using the Underwater Minecart, however other mods may add other carts that do have an effect.

This issue has been marked as stale because it has been inactive for 3 weeks. It will be closed if it remains inactive for another 3 weeks.

This issue has been closed since it has been inactive for 3 weeks since it was marked as stale.