diff --git a/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/AbstractRSQLVisitor.java b/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/AbstractRSQLVisitor.java
index 2183ae392..9db525381 100644
--- a/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/AbstractRSQLVisitor.java
+++ b/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/AbstractRSQLVisitor.java
@@ -57,7 +57,7 @@ public abstract class AbstractRSQLVisitor<A extends Enum<A> & RsqlQueryField> {
             if (!enumValue.isMap()) {
                 // sub entity need minimum 1 dot
                 if (!enumValue.getSubEntityAttributes().isEmpty() && split.length < 2) {
-                    if (enumValue.getSubEntityAttributes().size() == 1) { // single sub attribute - so default
+                    if (enumValue.getSubEntityAttributes().size() == 1) { // single sub attribute - so add is as a default
                         split = new String[] { split[0], enumValue.getSubEntityAttributes().get(0) };
                     } else {
                         throw createRSQLParameterUnsupportedException(node, null);
diff --git a/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/JpaQueryRsqlVisitorG2.java b/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/JpaQueryRsqlVisitorG2.java
index 52346680a..26d53527b 100644
--- a/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/JpaQueryRsqlVisitorG2.java
+++ b/hawkbit-repository/hawkbit-repository-jpa/src/main/java/org/eclipse/hawkbit/repository/jpa/rsql/JpaQueryRsqlVisitorG2.java
@@ -343,7 +343,7 @@ public class JpaQueryRsqlVisitorG2<A extends Enum<A> & RsqlQueryField, T>
     private Predicate toNotExistsSubQueryPredicate(final QuertPath queryField, final Path<Object> fieldPath, final Function<Expression<String>, Predicate> subQueryPredicateProvider) {
         // if a subquery the field's parent joins are not actually used
         if (!inOr) {
-            // so, if not in or (hence not reused) we remove them
+            // so, if not in or (hence not reused) we remove them. Parent shall be a Join
             root.getJoins().remove(fieldPath.getParentPath());
         }
 
@@ -365,7 +365,7 @@ public class JpaQueryRsqlVisitorG2<A extends Enum<A> & RsqlQueryField, T>
         }
         if (fieldPath instanceof MapJoin) {
             // Currently we support only string key. So below cast is safe.
-            return (Expression<String>) (((MapJoin<?, ?, ?>) pathOfString(fieldPath)).value());
+            return (Expression<String>) (((MapJoin<?, ?, ?>) fieldPath).value());
         }
         final String valueFieldName = enumField.getSubEntityMapTuple().map(Entry::getValue)
                 .orElseThrow(() -> new UnsupportedOperationException(