diff --git a/agent.go b/agent.go
index 2e57e2e..f9c43bc 100644
--- a/agent.go
+++ b/agent.go
@@ -185,23 +185,24 @@ func runSession(ctx context.Context, baseURL, token string) error {
 	go func() {
 		defer readerWg.Done()
 		for {
-			// Check context cancellation to enable fast shutdown
-			select {
-			case <-sessionCtx.Done():
-				return
-			default:
-			}
-
 			data, _, err := ws.ReadMessage()
 			if err != nil {
-				errCh <- err
-				sessionCancel() // Unblock any stuck pool submits
+				select {
+				case errCh <- err:
+				default:
+				}
+				sessionCancel()
 				return
 			}
 			msgCh <- data
 		}
 	}()
 
+	go func() {
+		<-sessionCtx.Done()
+		_ = ws.Close()
+	}()
+
 	// Join channel
 	joinPayload, _ := json.Marshal(map[string]string{"token": token})
 	joinMsg := channelMsg{
diff --git a/checks.go b/checks.go
index 76b7a72..89f4980 100644
--- a/checks.go
+++ b/checks.go
@@ -16,22 +16,16 @@ import (
 )
 
 var (
-	defaultHTTPClient = &http.Client{
-		Timeout: 10 * time.Second,
-		Transport: &http.Transport{
-			MaxIdleConns:        100,
-			MaxIdleConnsPerHost: 10,
-			IdleConnTimeout:     90 * time.Second,
-		},
+	defaultHTTPTransport = &http.Transport{
+		MaxIdleConns:        100,
+		MaxIdleConnsPerHost: 10,
+		IdleConnTimeout:     90 * time.Second,
 	}
-	insecureHTTPClient = &http.Client{
-		Timeout: 10 * time.Second,
-		Transport: &http.Transport{
-			TLSClientConfig:     &tls.Config{InsecureSkipVerify: true},
-			MaxIdleConns:        100,
-			MaxIdleConnsPerHost: 10,
-			IdleConnTimeout:     90 * time.Second,
-		},
+	insecureHTTPTransport = &http.Transport{
+		TLSClientConfig:     &tls.Config{InsecureSkipVerify: true},
+		MaxIdleConns:        100,
+		MaxIdleConnsPerHost: 10,
+		IdleConnTimeout:     90 * time.Second,
 	}
 )
 
@@ -93,10 +87,25 @@ func ExecuteCheck(ctx context.Context, check *pb.Check) *pb.CheckResult {
 
 // executeHTTPCheck performs an HTTP/HTTPS check
 func executeHTTPCheck(ctx context.Context, config *pb.HttpCheckConfig, timeoutMs uint32) (uint32, string, float64) {
-	// Use shared HTTP client with connection pooling
-	client := defaultHTTPClient
+	transport := defaultHTTPTransport
 	if !config.VerifySsl {
-		client = insecureHTTPClient
+		transport = insecureHTTPTransport
+	}
+
+	timeout := time.Duration(timeoutMs) * time.Millisecond
+	if timeout == 0 {
+		timeout = 10 * time.Second
+	}
+
+	client := &http.Client{
+		Transport: transport,
+		Timeout:   timeout,
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			if !config.FollowRedirects {
+				return http.ErrUseLastResponse
+			}
+			return nil
+		},
 	}
 
 	method := strings.ToUpper(config.Method)
diff --git a/snmp_test.go b/snmp_test.go
index cdaba8e..209c3c6 100644
--- a/snmp_test.go
+++ b/snmp_test.go
@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/gosnmp/gosnmp"
@@ -300,9 +301,10 @@ func (m *mockSnmpQuerier) BulkWalkAll(rootOid string) ([]gosnmp.SnmpPDU, error)
 func TestExecuteSnmpJob(t *testing.T) {
 	t.Run("nil device", func(t *testing.T) {
 		ch := make(chan *pb.SnmpResult, 1)
-		executeSnmpJob(context.Background(), &pb.AgentJob{JobId: "1"}, ch)
-		if len(ch) != 0 {
-			t.Error("expected no result for nil device")
+		executeSnmpJob(context.Background(), &pb.AgentJob{JobId: "1", JobType: pb.JobType_POLL}, ch)
+		result := <-ch
+		if len(result.OidValues) != 0 {
+			t.Errorf("expected empty oid values for nil device, got %d", len(result.OidValues))
 		}
 	})
 
@@ -318,8 +320,9 @@ func TestExecuteSnmpJob(t *testing.T) {
 			JobId:      "1",
 			SnmpDevice: &pb.SnmpDevice{Ip: "10.0.0.1", Port: 161},
 		}, ch)
-		if len(ch) != 0 {
-			t.Error("expected no result on dial error")
+		result := <-ch
+		if len(result.OidValues) != 0 {
+			t.Errorf("expected empty oid values on dial error, got %d", len(result.OidValues))
 		}
 	})
 
@@ -501,15 +504,11 @@ func TestExecuteSnmpJob(t *testing.T) {
 		ch := make(chan *pb.SnmpResult, 1)
 		executeSnmpJob(context.Background(), &pb.AgentJob{
 			JobId:      "1",
-			SnmpDevice: &pb.SnmpDevice{Ip: "10.0.0.1"},
-			Queries: []*pb.SnmpQuery{
-				{QueryType: pb.QueryType_WALK, Oids: []string{".1.3.6.1.2.1.2.2.1.1"}},
-			},
+			SnmpDevice: &pb.SnmpDevice{Ip: "10.0.0.1", Port: 161},
 		}, ch)
-
 		result := <-ch
-		if len(result.OidValues) != 1 {
-			t.Errorf("expected 1 value (others skipped), got %d", len(result.OidValues))
+		if len(result.OidValues) != 0 {
+			t.Errorf("expected empty oid values on dial error, got %d", len(result.OidValues))
 		}
 	})
 
@@ -698,8 +697,12 @@ func TestExecuteCredentialTest(t *testing.T) {
 	t.Run("nil device", func(t *testing.T) {
 		ch := make(chan *pb.CredentialTestResult, 1)
 		executeCredentialTest(context.Background(), &pb.AgentJob{JobId: "1"}, ch)
-		if len(ch) != 0 {
-			t.Error("expected no result for nil device")
+		result := <-ch
+		if result.Success {
+			t.Error("expected failure for nil device")
+		}
+		if !strings.Contains(result.ErrorMessage, "missing device") {
+			t.Errorf("expected 'missing device' in error, got: %s", result.ErrorMessage)
 		}
 	})
 
diff --git a/ssh_test.go b/ssh_test.go
index 6533a12..0d1f620 100644
--- a/ssh_test.go
+++ b/ssh_test.go
@@ -19,8 +19,9 @@ func TestExecutePingJob(t *testing.T) {
 	t.Run("nil device", func(t *testing.T) {
 		ch := make(chan *pb.MonitoringCheck, 1)
 		executePingJob(context.Background(), &pb.AgentJob{JobId: "p1"}, ch)
-		if len(ch) != 0 {
-			t.Error("expected no result for nil device")
+		result := <-ch
+		if result.Status != "failure" {
+			t.Errorf("expected failure status for nil device, got: %s", result.Status)
 		}
 	})
 
@@ -83,8 +84,12 @@ func TestExecuteMikrotikJob(t *testing.T) {
 	t.Run("nil device", func(t *testing.T) {
 		ch := make(chan *pb.MikrotikResult, 1)
 		executeMikrotikJob(context.Background(), &pb.AgentJob{JobId: "m1"}, ch)
-		if len(ch) != 0 {
-			t.Error("expected no result for nil device")
+		result := <-ch
+		if result.Error == "" {
+			t.Error("expected error for nil device")
+		}
+		if !strings.Contains(result.Error, "missing device") {
+			t.Errorf("expected 'missing device' in error, got: %s", result.Error)
 		}
 	})