Use the delete function where a delete inteded.

src/main/java/xyz/alexcrea/cuanvil/api/ConflictAPI.java

@@ -118,7 +118,7 @@ public class ConflictAPI {
         ConfigHolder.CONFLICT_HOLDER.getConflictManager().removeConflict(conflict);
 
         // Write as null and save to file
-        ConfigHolder.CONFLICT_HOLDER.getConfig().set(conflict.getName(), null);
+        ConfigHolder.CONFLICT_HOLDER.delete(conflict.getName());
         prepareSaveTask();
 
         // Remove from gui

src/main/java/xyz/alexcrea/cuanvil/api/CustomAnvilRecipeApi.java

@@ -74,7 +74,7 @@ public class CustomAnvilRecipeApi {
         ConfigHolder.CUSTOM_RECIPE_HOLDER.getRecipeManager().cleanRemove(recipe);
 
         // Write as null and save to file
-        ConfigHolder.CUSTOM_RECIPE_HOLDER.getConfig().set(recipe.getName(), null);
+        ConfigHolder.CUSTOM_RECIPE_HOLDER.delete(recipe.getName());
         prepareSaveTask();
 
         // Remove from gui

src/main/java/xyz/alexcrea/cuanvil/api/MaterialGroupApi.java

@@ -145,7 +145,7 @@ public class MaterialGroupApi {
         ConfigHolder.ITEM_GROUP_HOLDER.getItemGroupsManager().groupMap.remove(group.getName());
 
         // Write as null and save to file
-        ConfigHolder.ITEM_GROUP_HOLDER.getConfig().set(group.getName(), null);
+        ConfigHolder.ITEM_GROUP_HOLDER.delete(group.getName());
         prepareSaveTask();
 
         // Remove from gui

src/main/java/xyz/alexcrea/cuanvil/config/ConfigHolder.java

@@ -251,6 +251,15 @@ public abstract class ConfigHolder {
             return this.deletedListConfig.getBoolean(objectPath, false);
         }
 
+        /**
+         * Delete a certain object by its path. do not save the config.
+         * @param objectPath The object path to delete.
+         * @return True if successful.
+         */
+        public boolean delete(String objectPath){
+            return delete(objectPath, false, false);
+        }
+
         /**
          * Delete a certain object by its path.
          * @param objectPath The object path to delete.

src/main/java/xyz/alexcrea/cuanvil/gui/config/list/elements/CustomRecipeSubSettingGui.java

@@ -120,7 +120,7 @@ public class CustomRecipeSubSettingGui extends MappedToListSubSettingGui {
             cleanAndBeUnusable();
 
             // Update config file storage
-            ConfigHolder.CUSTOM_RECIPE_HOLDER.getConfig().set(this.anvilRecipe.toString(), null);
+            ConfigHolder.CUSTOM_RECIPE_HOLDER.delete(this.anvilRecipe.toString());
 
             // Save
             boolean success = true;

src/main/java/xyz/alexcrea/cuanvil/gui/config/list/elements/EnchantConflictSubSettingGui.java

@@ -127,7 +127,7 @@ public class EnchantConflictSubSettingGui extends MappedToListSubSettingGui impl
             cleanAndBeUnusable();
 
             // Update config file storage
-            ConfigHolder.CONFLICT_HOLDER.getConfig().set(this.enchantConflict.toString(), null);
+            ConfigHolder.CONFLICT_HOLDER.delete(this.enchantConflict.toString());
 
             // Save
             boolean success = true;

src/main/java/xyz/alexcrea/cuanvil/gui/config/list/elements/GroupConfigSubSettingGui.java

@@ -129,7 +129,7 @@ public class GroupConfigSubSettingGui extends MappedToListSubSettingGui implemen
             cleanAndBeUnusable();
 
             // Update config file storage
-            ConfigHolder.CUSTOM_RECIPE_HOLDER.getConfig().set(this.group.getName(), null);
+            ConfigHolder.CUSTOM_RECIPE_HOLDER.delete(this.group.getName());
 
             // Save
             boolean success = true;

src/main/java/xyz/alexcrea/cuanvil/gui/config/settings/DoubleSettingGui.java

@@ -316,7 +316,11 @@ public class DoubleSettingGui extends AbstractSettingGui {
     @Override
     public boolean onSave() {
         if(isNull()){
-            this.holder.config.getConfig().set(this.holder.configPath, null);
+            if(this.holder.config instanceof ConfigHolder.DeletableResource deletableResource){
+                deletableResource.delete(this.holder.configPath);
+            }else{
+                this.holder.config.getConfig().set(this.holder.configPath, null);
+            }
         }else{
             this.holder.config.getConfig().set(this.holder.configPath, now.doubleValue());
         }