diff --git a/.github/workflows/common-performance.yml b/.github/workflows/common-performance.yml
index a5d941bf..672c9072 100644
--- a/.github/workflows/common-performance.yml
+++ b/.github/workflows/common-performance.yml
@@ -266,6 +266,7 @@ jobs:
       - name: Generate results
         if: always()
         run: |
+          Remove-Item -Path . -Name "docker/speedtests/speedtests.test" -Force | Out-Null
           New-Item -Path . -Name "${{ env.DEST_ARTIFACT }}" -ItemType "directory" -Force | Out-Null
           Move-Item ${{ github.workspace }}/docker/speedtests/ ${{ env.DEST_ARTIFACT }}/
           Move-Item ${{ github.workspace }}/build/*.log ${{ env.DEST_ARTIFACT }}/
diff --git a/.github/workflows/performance.yml b/.github/workflows/performance.yml
index fb31ff22..f73aae09 100644
--- a/.github/workflows/performance.yml
+++ b/.github/workflows/performance.yml
@@ -122,4 +122,5 @@ jobs:
             ${{ github.token }}
         with:
           name: ${{ env.ARTIFACT_KEY }}
+          separate-directories: true
           delete-merged: true
diff --git a/backend/quicly-go b/backend/quicly-go
index 4f5328cd..6806d391 160000
--- a/backend/quicly-go
+++ b/backend/quicly-go
@@ -1 +1 @@
-Subproject commit 4f5328cd04af072aa585f4c1545034b3573a80ae
+Subproject commit 6806d391f9e1510c9b6f129a2418407bfc1f9b5a
diff --git a/workers/client/client_network.go b/workers/client/client_network.go
index e15eab60..63b237f5 100644
--- a/workers/client/client_network.go
+++ b/workers/client/client_network.go
@@ -718,10 +718,8 @@ func copyBuffer(dst WriterTimeout, src ReaderTimeout, buf []byte, timeoutDst tim
 		logger.Debug("[%d][%s] w,r: %d,%v **", *counter, prefix, 0, er)
 	}
 
-	if er != nil {
-		//if er != io.EOF {
+	if er != nil && er != io.EOF {
 		err = er
-		//}
 	}
 	return written, read, err
 }
diff --git a/workers/server/server_network.go b/workers/server/server_network.go
index 5f1691cd..5ff47487 100644
--- a/workers/server/server_network.go
+++ b/workers/server/server_network.go
@@ -453,10 +453,8 @@ func copyBuffer(dst WriterTimeout, src ReaderTimeout, buf []byte, timeoutDst tim
 		logger.Debug("[%d][%s] w,r: %d,%v **", *counter, prefix, 0, er)
 	}
 
-	if er != nil {
-		//if er != io.EOF {
+	if er != nil && er != io.EOF {
 		err = er
-		//}
 	}
 	return written, read, err
 }