diff --git a/client/captcha_v2.go b/client/captcha_v2.go
index 50ca5c9..1a3b925 100644
--- a/client/captcha_v2.go
+++ b/client/captcha_v2.go
@@ -180,8 +180,8 @@ func (s *captchaV2Session) solveOnce(captchaErr *VkCaptchaError) (string, error)
 	log.Printf("v2 captcha pow solved")
 
 	base := captchaV2BaseValues(captchaErr.SessionToken)
-	if _, err := s.captchaRequest("captchaNotRobot.settings", base); err != nil {
-		return "", fmt.Errorf("captcha settings failed: %w", err)
+	if _, settingsErr := s.captchaRequest("captchaNotRobot.settings", base); settingsErr != nil {
+		return "", fmt.Errorf("captcha settings failed: %w", settingsErr)
 	}
 
 	browserFP, err := captchaV2BrowserFP()
@@ -233,7 +233,9 @@ func (s *captchaV2Session) solveOnce(captchaErr *VkCaptchaError) (string, error)
 		showType = stErr.ShowType
 	}
 
-	_, _ = s.captchaRequest("captchaNotRobot.endSession", base)
+	if _, endErr := s.captchaRequest("captchaNotRobot.endSession", base); endErr != nil {
+		log.Printf("v2 captcha endSession failed: %v", endErr)
+	}
 	return token, nil
 }
 
@@ -269,7 +271,10 @@ func (s *captchaV2Session) fetchCaptchaHTML(redirectURI string) (string, error)
 
 func (s *captchaV2Session) fetchDebugInfo(scriptURL string) (string, error) {
 	if cached, ok := captchaV2DebugCache.Load(scriptURL); ok {
-		return cached.(string), nil
+		if cachedDebugInfo, ok := cached.(string); ok {
+			return cachedDebugInfo, nil
+		}
+		captchaV2DebugCache.Delete(scriptURL)
 	}
 	body, err := s.doRaw(fhttp.MethodGet, scriptURL, nil, map[string]string{
 		"Accept":  "text/javascript,*/*",
diff --git a/server/main.go b/server/main.go
index 704fa64..432802c 100644
--- a/server/main.go
+++ b/server/main.go
@@ -284,14 +284,6 @@ type bondFrame struct {
 	data []byte
 }
 
-func readBondHello(r io.Reader) (bondHello, error) {
-	var hdr [17]byte
-	if _, err := io.ReadFull(r, hdr[:]); err != nil {
-		return bondHello{}, err
-	}
-	return parseBondHelloHeader(hdr[:])
-}
-
 func readBondHelloAfterMagic(r io.Reader, magic [4]byte) (bondHello, error) {
 	var hdr [17]byte
 	copy(hdr[0:4], magic[:])
@@ -662,10 +654,6 @@ func (c *bondServerConn) writeToNextLane(typ byte, seq uint64, data []byte, lane
 	}
 }
 
-func handleBondServerStream(ctx context.Context, stream *smux.Stream, connectAddr string) {
-	handleBondServerStreamWithHello(ctx, stream, connectAddr, readBondHello)
-}
-
 func handleBondServerStreamAfterMagic(ctx context.Context, stream *smux.Stream, connectAddr string, magic [4]byte) {
 	handleBondServerStreamWithHello(ctx, stream, connectAddr, func(r io.Reader) (bondHello, error) {
 		return readBondHelloAfterMagic(r, magic)