diff --git a/CHANGELOG b/CHANGELOG
index fbf1229e7..cb39b64e0 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,6 @@
+KeepassDX (2.5.0.0beta20)
+ * Fix nested groups no longer visible in V1 databases
+
 KeepassDX (2.5.0.0beta20)
  * Fix a major bug that displays an entry history
 
diff --git a/app/build.gradle b/app/build.gradle
index f1eed1aeb..b0b10d4f7 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -11,8 +11,8 @@ android {
         applicationId "com.kunzisoft.keepass"
         minSdkVersion 14
         targetSdkVersion 27
-        versionCode = 20
-        versionName = "2.5.0.0beta20"
+        versionCode = 21
+        versionName = "2.5.0.0beta21"
         multiDexEnabled true
 
         testApplicationId = "com.kunzisoft.keepass.tests"
diff --git a/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV3.kt b/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV3.kt
index cd56208c7..c1e68a3b4 100644
--- a/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV3.kt
+++ b/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV3.kt
@@ -27,7 +27,6 @@ import java.io.InputStream
 import java.security.DigestOutputStream
 import java.security.MessageDigest
 import java.security.NoSuchAlgorithmException
-import java.util.*
 
 /**
  * @author Naomaru Itoi <nao></nao>@phoneid.org>
@@ -76,50 +75,44 @@ class PwDatabaseV3 : PwDatabase<PwGroupV3, PwEntryV3>() {
         numKeyEncRounds = DEFAULT_ENCRYPTION_ROUNDS
     }
 
-    private fun assignGroupsChildren(parent: PwGroupV3) {
-        val levelToCheck = parent.level + 1
-        var startFromParentPosition = false
-        for (groupToCheck in getGroupIndexes()) {
-            rootGroup?.let { root ->
-                if (root.nodeId == parent.nodeId || groupToCheck.nodeId == parent.nodeId) {
-                    startFromParentPosition = true
-                }
-            }
-            if (startFromParentPosition) {
-                if (groupToCheck.level < levelToCheck)
-                    break
-                else if (groupToCheck.level == levelToCheck)
-                    parent.addChildGroup(groupToCheck)
-            }
+    private fun buildTreeGroups(previousGroup: PwGroupV3, currentGroup: PwGroupV3, groupIterator: Iterator<PwGroupV3>) {
+
+        if (currentGroup.parent == null && (previousGroup.level + 1) == currentGroup.level) {
+            // Current group has an increment level compare to the previous, current group is a child
+            previousGroup.addChildGroup(currentGroup)
+            currentGroup.parent = previousGroup
+        } else if (previousGroup.parent != null && previousGroup.level == currentGroup.level) {
+            // In the same level, previous parent is the same as previous group
+            previousGroup.parent!!.addChildGroup(currentGroup)
+            currentGroup.parent = previousGroup.parent
+        } else if (previousGroup.parent != null) {
+            // Previous group has a higher level than the current group, check it's parent
+            buildTreeGroups(previousGroup.parent!!, currentGroup, groupIterator)
         }
-    }
 
-    private fun assignEntriesChildren(parent: PwGroupV3) {
-        for (entry in getEntryIndexes()) {
-            if (entry.parent!!.nodeId == parent.nodeId)
-                parent.addChildEntry(entry)
-        }
-    }
-
-    private fun constructTreeFromIndex(currentGroup: PwGroupV3) {
-
-        assignGroupsChildren(currentGroup)
-        assignEntriesChildren(currentGroup)
-
-        // set parent in child entries (normally useless but to be sure or to update parent metadata)
-        for (childEntry in currentGroup.getChildEntries()) {
-            childEntry.parent = currentGroup
-        }
-        // recursively construct child groups
-        for (childGroup in currentGroup.getChildGroups()) {
-            childGroup.parent = currentGroup
-            constructTreeFromIndex(childGroup)
+        // Next current group
+        if (groupIterator.hasNext()){
+            buildTreeGroups(currentGroup, groupIterator.next(), groupIterator)
         }
     }
 
     fun constructTreeFromIndex() {
         rootGroup?.let {
-            constructTreeFromIndex(it)
+
+            // add each group
+            val groupIterator = getGroupIndexes().iterator()
+            if (groupIterator.hasNext())
+                buildTreeGroups(it, groupIterator.next(), groupIterator)
+
+            // add each child
+            for (currentEntry in getEntryIndexes()) {
+                if (currentEntry.parent != null) {
+                    // Only the parent id is known so complete the info
+                    val parentGroupRetrieve = getGroupById(currentEntry.parent!!.nodeId)
+                    parentGroupRetrieve?.addChildEntry(currentEntry)
+                    currentEntry.parent = parentGroupRetrieve
+                }
+            }
         }
     }
 
diff --git a/fastlane/metadata/android/en-US/changelogs/21.txt b/fastlane/metadata/android/en-US/changelogs/21.txt
new file mode 100644
index 000000000..6cf34ea25
--- /dev/null
+++ b/fastlane/metadata/android/en-US/changelogs/21.txt
@@ -0,0 +1,9 @@
+ * Add lock button always visible
+ * New connection workflow
+ * Code refactored in Kotlin
+ * Better notification implementation
+ * Better views for large screen
+ * Magikeyboard enhancement
+ * Fix Recycle Bin
+ * Fix memory when load database
+ * Fix bugs that displays bad entries and groups (2.5.0.0beta19-20)
\ No newline at end of file
diff --git a/fastlane/metadata/android/fr-FR/changelogs/21.txt b/fastlane/metadata/android/fr-FR/changelogs/21.txt
new file mode 100644
index 000000000..f703e3393
--- /dev/null
+++ b/fastlane/metadata/android/fr-FR/changelogs/21.txt
@@ -0,0 +1,9 @@
+ * Ajout du bouton de lock toujours visible
+ * Nouveau workflow de connexion
+ * Code refactorisé en Kotlin
+ * Meilleure implementation des notifications
+ * Meilleures vues pour les écrans larges
+ * Amélioration du Magikeyboard
+ * Correction de la Corbeille
+ * Correction de la mémoire lors du chargement de base de données
+ * Correction de bugs d'affichage des entrée et groupes (2.5.0.0beta19-20)
\ No newline at end of file