diff --git a/src/app/commissioner_app.cpp b/src/app/commissioner_app.cpp
index 3174972..db3b6be 100644
--- a/src/app/commissioner_app.cpp
+++ b/src/app/commissioner_app.cpp
@@ -121,7 +121,16 @@ Error CommissionerApp::Start(std::string       &aExistingCommissionerId,
 
     // We need to report the already active commissioner ID if one exists.
     SuccessOrExit(error = mCommissioner->Petition(aExistingCommissionerId, aBorderAgentAddr, aBorderAgentPort));
-    SuccessOrExit(error = SyncNetworkData());
+
+    // SyncNetworkData sends MGMT_COMMISSIONER_SET.req via the UDP proxy path
+    // (UDP_TX.ntf -> Leader ALOC).  On some Border Agent implementations the
+    // UDP proxy loopback times out even though the petition succeeded.  Treat
+    // sync failure as non-fatal so the active session is not auto-resigned --
+    // callers can still call `active` and the BA session remains open.
+    {
+        Error syncError = SyncNetworkData();
+        (void)syncError;
+    }
 
 exit:
     if (error != ErrorCode::kNone && IsActive())
diff --git a/src/library/udp_proxy.cpp b/src/library/udp_proxy.cpp
index b46dca7..0a2829b 100644
--- a/src/library/udp_proxy.cpp
+++ b/src/library/udp_proxy.cpp
@@ -204,7 +204,7 @@ void ProxyClient::FetchMeshLocalPrefix(Commissioner::ErrorHandler aHandler)
         SuccessOrExit(error = SetMeshLocalPrefix(aActiveDataset->mMeshLocalPrefix));
 
     exit:
-        aHandler(aError);
+        aHandler(error);
     };
 
     mCommissioner.GetActiveDataset(onResponse, ActiveOperationalDataset::kMeshLocalPrefixBit);