Paper/nms-patches/EntityMinecartMobSpawner.patch

--- a/net/minecraft/server/EntityMinecartMobSpawner.java
+++ b/net/minecraft/server/EntityMinecartMobSpawner.java
@@ -46,4 +46,10 @@
         super.tick();
         this.a.c();
     }
+
+    // CraftBukkit start
+    public boolean bM() {
+        return true;
+    }
+    // CraftBukkit end
 }