diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0e4cfe3ac8a..ce6c7c162aa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,7 +33,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - The global default directory for storing PDFs is now the subdirectory "JabRef" in the user's home.
 - We reworked the Define study parameters dialog. [#9123](https://github.com/JabRef/jabref/pull/9123)
 - We simplified the actions to fast-resolve duplicates to 'Keep Left', 'Keep Right', 'Keep Both' and 'Keep Merged'. [#9056](https://github.com/JabRef/jabref/issues/9056)
-
+- We fixed an issue where a message about changed metadata would occur on saving although nothing changed [#9159](https://github.com/JabRef/jabref/issues/9159)
 
 ### Fixed
 
diff --git a/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanup.java b/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanup.java
index 0d1cf5c5ad6..1594bdb4aab 100644
--- a/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanup.java
+++ b/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanup.java
@@ -105,15 +105,15 @@ public Formatter getFormatter() {
     }
 
     @Override
-    public boolean equals(Object o) {
-        if (this == o) {
+    public boolean equals(Object obj) {
+        if (this == obj) {
             return true;
         }
-        if (o instanceof FieldFormatterCleanup) {
-            FieldFormatterCleanup that = (FieldFormatterCleanup) o;
-            return Objects.equals(field, that.field) && Objects.equals(formatter, that.formatter);
+        if (!(obj instanceof FieldFormatterCleanup)) {
+            return false;
         }
-        return false;
+        FieldFormatterCleanup other = (FieldFormatterCleanup) obj;
+        return Objects.equals(field, other.field) && Objects.equals(formatter, other.formatter);
     }
 
     @Override
diff --git a/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanups.java b/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanups.java
index ce53b68d144..153ee3be486 100644
--- a/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanups.java
+++ b/src/main/java/org/jabref/logic/cleanup/FieldFormatterCleanups.java
@@ -206,4 +206,26 @@ private static Formatter getFormatterFromString(String formatterName) {
         }
         return new IdentityFormatter();
     }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(actions, enabled);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof FieldFormatterCleanups)) {
+            return false;
+        }
+        FieldFormatterCleanups other = (FieldFormatterCleanups) obj;
+        return Objects.equals(actions, other.actions) && (enabled == other.enabled);
+    }
+
+    @Override
+    public String toString() {
+        return "FieldFormatterCleanups [enabled=" + enabled + ", actions=" + actions + "]";
+    }
 }
diff --git a/src/main/java/org/jabref/model/metadata/ContentSelector.java b/src/main/java/org/jabref/model/metadata/ContentSelector.java
index 1d51a893aa9..d2c633f6396 100644
--- a/src/main/java/org/jabref/model/metadata/ContentSelector.java
+++ b/src/main/java/org/jabref/model/metadata/ContentSelector.java
@@ -26,7 +26,7 @@ public boolean equals(Object o) {
         if (this == o) {
             return true;
         }
-        if (o == null || getClass() != o.getClass()) {
+        if ((o == null) || (getClass() != o.getClass())) {
             return false;
         }
 
@@ -35,6 +35,11 @@ public boolean equals(Object o) {
                 Objects.equals(values, that.values);
     }
 
+    @Override
+    public String toString() {
+        return "ContentSelector [field=" + field + ", values=" + values + "]";
+    }
+
     @Override
     public int hashCode() {
         return Objects.hash(field, values);
diff --git a/src/main/java/org/jabref/model/metadata/MetaData.java b/src/main/java/org/jabref/model/metadata/MetaData.java
index 9b0ed2ae856..1ef1a0976b1 100644
--- a/src/main/java/org/jabref/model/metadata/MetaData.java
+++ b/src/main/java/org/jabref/model/metadata/MetaData.java
@@ -375,7 +375,14 @@ public boolean equals(Object o) {
 
     @Override
     public int hashCode() {
-        return Objects.hash(groupsRoot.getValue(), encoding, encodingExplicitlySupplied, saveOrderConfig, citeKeyPatterns, userFileDirectory,
-                defaultCiteKeyPattern, saveActions, mode, isProtected, defaultFileDirectory);
+        return Objects.hash(isProtected, groupsRoot.getValue(), encoding, encodingExplicitlySupplied, saveOrderConfig, citeKeyPatterns, userFileDirectory,
+                laTexFileDirectory, defaultCiteKeyPattern, saveActions, mode, defaultFileDirectory, contentSelectors);
     }
+
+    @Override
+    public String toString() {
+        return "MetaData [citeKeyPatterns=" + citeKeyPatterns + ", userFileDirectory=" + userFileDirectory + ", laTexFileDirectory=" + laTexFileDirectory + ", groupsRoot=" + groupsRoot + ", encoding=" + encoding + ", saveOrderConfig=" + saveOrderConfig + ", defaultCiteKeyPattern=" + defaultCiteKeyPattern + ", saveActions=" + saveActions + ", mode=" + mode + ", isProtected=" + isProtected + ", defaultFileDirectory=" + defaultFileDirectory + ", contentSelectors=" + contentSelectors + ", encodingExplicitlySupplied=" + encodingExplicitlySupplied + "]";
+    }
+
+
 }