diff --git a/CHANGELOG.unreleased.md b/CHANGELOG.unreleased.md
index eb53418f197..55950e1dc0d 100644
--- a/CHANGELOG.unreleased.md
+++ b/CHANGELOG.unreleased.md
@@ -28,6 +28,7 @@ For upgrade instructions, please check the [migration guide](MIGRATIONS.released
 - Fixed reading sharded Zarr 3 data from the local file system. [#7321](https://github.com/scalableminds/webknossos/pull/7321)
 - Fixed no-bucket data zipfile when downloading volume annotations. [#7323](https://github.com/scalableminds/webknossos/pull/7323)
 - Fixed too tight assertions when saving annotations, leading to failed save requests. [#7326](https://github.com/scalableminds/webknossos/pull/7326)
+- Fixed a bug when saving large amounts of skeleton annotation data at once. [#7329](https://github.com/scalableminds/webknossos/pull/7329)
 
 ### Removed
 
diff --git a/frontend/javascripts/oxalis/model/sagas/save_saga_constants.ts b/frontend/javascripts/oxalis/model/sagas/save_saga_constants.ts
index 28d90432790..3633a96e587 100644
--- a/frontend/javascripts/oxalis/model/sagas/save_saga_constants.ts
+++ b/frontend/javascripts/oxalis/model/sagas/save_saga_constants.ts
@@ -14,11 +14,11 @@ export const SETTINGS_MAX_RETRY_COUNT = 20; // 20 * 15s == 5m
 export const MAXIMUM_ACTION_COUNT_PER_BATCH = {
   skeleton: 5000,
   volume: 1000, // Since volume saving is slower, use a lower value here.
-  mapping: 5000,
+  mapping: Infinity, // The back-end does not accept transactions for mappings.
 } as const;
 
 export const MAXIMUM_ACTION_COUNT_PER_SAVE = {
   skeleton: 15000,
   volume: 3000,
-  mapping: 15000,
+  mapping: Infinity, // The back-end does not accept transactions for mappings.
 } as const;
diff --git a/webknossos-tracingstore/app/com/scalableminds/webknossos/tracingstore/controllers/TracingController.scala b/webknossos-tracingstore/app/com/scalableminds/webknossos/tracingstore/controllers/TracingController.scala
index 77bc1dcdae4..cf28ab9e0f5 100644
--- a/webknossos-tracingstore/app/com/scalableminds/webknossos/tracingstore/controllers/TracingController.scala
+++ b/webknossos-tracingstore/app/com/scalableminds/webknossos/tracingstore/controllers/TracingController.scala
@@ -187,10 +187,29 @@ trait TracingController[T <: GeneratedMessage, Ts <: GeneratedMessage] extends C
       _ <- bool2Fox(
         previousActionGroupsToCommit
           .exists(_.transactionGroupIndex == 0) || updateGroup.transactionGroupCount == 1) ?~> s"Trying to commit a transaction without a group that has transactionGroupIndex 0."
-      commitResult <- commitUpdates(tracingId, previousActionGroupsToCommit :+ updateGroup, userToken)
+      concatenatedGroup = concatenateUpdateGroupsOfTransaction(previousActionGroupsToCommit, updateGroup)
+      commitResult <- commitUpdates(tracingId, List(concatenatedGroup), userToken)
       _ <- tracingService.removeAllUncommittedFor(tracingId, updateGroup.transactionId)
     } yield commitResult
 
+  private def concatenateUpdateGroupsOfTransaction(previousActionGroups: List[UpdateActionGroup[T]],
+                                                   lastActionGroup: UpdateActionGroup[T]): UpdateActionGroup[T] =
+    if (previousActionGroups.isEmpty) lastActionGroup
+    else {
+      val allActionGroups = previousActionGroups :+ lastActionGroup
+      UpdateActionGroup[T](
+        version = lastActionGroup.version,
+        timestamp = lastActionGroup.timestamp,
+        authorId = lastActionGroup.authorId,
+        actions = allActionGroups.flatMap(_.actions),
+        stats = lastActionGroup.stats, // the latest stats do count
+        info = lastActionGroup.info, // frontend sets this identically for all groups of transaction
+        transactionId = f"${lastActionGroup.transactionId}-concatenated",
+        transactionGroupCount = 1,
+        transactionGroupIndex = 0,
+      )
+    }
+
   // Perform version check and commit the passed updates
   private def commitUpdates(tracingId: String,
                             updateGroups: List[UpdateActionGroup[T]],
@@ -207,8 +226,7 @@ trait TracingController[T <: GeneratedMessage, Ts <: GeneratedMessage] extends C
     remoteWebKnossosClient.reportTracingUpdates(report).flatMap { _ =>
       updateGroups.foldLeft(currentCommittedVersion) { (previousVersion, updateGroup) =>
         previousVersion.flatMap { prevVersion: Long =>
-          val versionIncrement = if (updateGroup.transactionGroupIndex == 0) 1 else 0 // version increment happens at the start of each transaction
-          if (prevVersion + versionIncrement == updateGroup.version) {
+          if (prevVersion + 1 == updateGroup.version) {
             tracingService
               .handleUpdateGroup(tracingId, updateGroup, prevVersion, userToken)
               .flatMap(