The name of cave_vines_body and cave_vines_head is the same ("Cave Vines") despite them being different blocks. Note that the IDs themselves are also inconsistent with similar blocks such as weeping vines (
MC-213765). The translation of cave_vines_body should be changed to "Cave Vines Plant", while the translation of cave_vines_head should be left as "Cave Vines".
To reproduce this bug, run the command
Notice how both types of cave vines blocks share the same name.