diff --git a/libv2ray_main.go b/libv2ray_main.go
index 1c297fb..cdff01d 100644
--- a/libv2ray_main.go
+++ b/libv2ray_main.go
@@ -190,7 +190,7 @@ func MeasureOutboundDelay(ConfigureFileContent string, url string) (int64, error
 
 // CheckVersionX returns the library and Xray versions
 func CheckVersionX() string {
-	var version = 33
+	var version = 32
 	return fmt.Sprintf("Lib v%d, Xray-core v%s", version, core.Version())
 }
 
@@ -237,12 +237,12 @@ func (x *CoreController) doStartLoop(configContent string) error {
 // measureInstDelay measures the delay for an instance to a given URL
 func measureInstDelay(ctx context.Context, inst *core.Instance, url string) (int64, error) {
 	if inst == nil {
-		return -1, errors.New("core instance is nil")
+		return -1, errors.New("nil instance")
 	}
 
 	tr := &http.Transport{
 		TLSHandshakeTimeout: 6 * time.Second,
-		DisableKeepAlives:   false,
+		DisableKeepAlives:   true,
 		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
 			dest, err := corenet.ParseDestination(fmt.Sprintf("%s:%s", network, addr))
 			if err != nil {
@@ -261,65 +261,18 @@ func measureInstDelay(ctx context.Context, inst *core.Instance, url string) (int
 		url = "https://www.google.com/generate_204"
 	}
 
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	req, _ := http.NewRequestWithContext(ctx, "GET", url, nil)
+	start := time.Now()
+	resp, err := client.Do(req)
 	if err != nil {
-		return -1, fmt.Errorf("failed to create HTTP request: %w", err)
+		return -1, err
 	}
+	defer resp.Body.Close()
 
-	var minDuration int64 = -1
-	success := false
-	var lastErr error
-
-	// Add exception handling and increase retry attempts
-	const attempts = 2
-	for i := 0; i < attempts; i++ {
-		select {
-		case <-ctx.Done():
-			// Return immediately when context is canceled
-			if !success {
-				return -1, ctx.Err()
-			}
-			return minDuration, nil
-		default:
-			// Continue execution
-		}
-
-		start := time.Now()
-		resp, err := client.Do(req)
-		if err != nil {
-			lastErr = err
-			continue
-		}
-
-		// Ensure response body is closed
-		defer func(resp *http.Response) {
-			if resp != nil && resp.Body != nil {
-				resp.Body.Close()
-			}
-		}(resp)
-
-		if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNoContent {
-			lastErr = fmt.Errorf("invalid status: %s", resp.Status)
-			continue
-		}
-
-		// Handle possible errors when reading response body
-		if _, err := io.Copy(io.Discard, resp.Body); err != nil {
-			lastErr = fmt.Errorf("failed to read response body: %w", err)
-			continue
-		}
-
-		duration := time.Since(start).Milliseconds()
-		if !success || duration < minDuration {
-			minDuration = duration
-		}
-
-		success = true
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNoContent {
+		return -1, fmt.Errorf("invalid status: %s", resp.Status)
 	}
-	if !success {
-		return -1, lastErr
-	}
-	return minDuration, nil
+	return time.Since(start).Milliseconds(), nil
 }
 
 // Log writer implementation