diff --git a/cmd/server/tests/opds_test.go b/cmd/server/tests/opds_test.go
index c5413c5..d35c9ce 100644
--- a/cmd/server/tests/opds_test.go
+++ b/cmd/server/tests/opds_test.go
@@ -12,7 +12,11 @@ import (
 // TestOPDSEndpoints tests OPDS (Open Publication Distribution System) endpoints
 func TestOPDSEndpoints(t *testing.T) {
 	setup := setupTestServer(t)
-	_ = createTestMediaItemID(t, setup.Server)
+	// Create ALL media items needed for ALL subtests BEFORE any t.Run (following Kobo pattern)
+	_ = createTestMediaItemID(t, setup)
+	bookID1 := createTestMediaItemID(t, setup)
+	bookID2 := createTestMediaItemID(t, setup)
+	bookID3 := createTestMediaItemID(t, setup)
 	client := &http.Client{}
 
 	t.Run("GetDeviceCatalog_WithoutDeviceAuth", func(t *testing.T) {
@@ -145,9 +149,8 @@ func TestOPDSEndpoints(t *testing.T) {
 	t.Run("DownloadBook_ValidIDs", func(t *testing.T) {
 		deviceSetup := setupDeviceTest(t)
 		device := deviceSetup.CreateDevice(t, "Test OPDS Device", "koreader", "opds-download-test")
-		bookID := createTestMediaItemID(t, setup.Server)
 
-		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID, nil)
+		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID1, nil)
 		httpReq.Header.Set("Authorization", "Bearer "+device.AuthToken)
 
 		resp, err := client.Do(httpReq)
@@ -182,9 +185,8 @@ func TestOPDSEndpoints(t *testing.T) {
 	t.Run("GetCoverImage_ValidIDs", func(t *testing.T) {
 		deviceSetup := setupDeviceTest(t)
 		device := deviceSetup.CreateDevice(t, "Test OPDS Device", "koreader", "opds-cover-test")
-		bookID := createTestMediaItemID(t, setup.Server)
 
-		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/cover/"+bookID, nil)
+		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/cover/"+bookID2, nil)
 		httpReq.Header.Set("Authorization", "Bearer "+device.AuthToken)
 
 		resp, err := client.Do(httpReq)
@@ -209,9 +211,8 @@ func TestOPDSEndpoints(t *testing.T) {
 	t.Run("ListFormats_ValidDeviceID", func(t *testing.T) {
 		deviceSetup := setupDeviceTest(t)
 		device := deviceSetup.CreateDevice(t, "Test OPDS Device", "koreader", "opds-formats-test")
-		bookID := createTestMediaItemID(t, setup.Server)
 
-		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/formats/"+bookID, nil)
+		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/formats/"+bookID3, nil)
 		httpReq.Header.Set("Authorization", "Bearer "+device.AuthToken)
 
 		resp, err := client.Do(httpReq)
@@ -226,16 +227,19 @@ func TestOPDSEndpoints(t *testing.T) {
 // TestOPDSConversion tests on-the-fly conversion for downloads
 func TestOPDSConversion(t *testing.T) {
 	setup := setupTestServer(t)
-	_ = createTestMediaItemID(t, setup.Server)
+	// Create ALL media items needed for ALL subtests BEFORE any t.Run (following Kobo pattern)
+	_ = createTestMediaItemID(t, setup)
+	bookID1 := createTestMediaItemID(t, setup)
+	bookID2 := createTestMediaItemID(t, setup)
+	bookID3 := createTestMediaItemID(t, setup)
 	client := &http.Client{}
 
 	t.Run("DownloadKEPUB_FormatParameter", func(t *testing.T) {
 		deviceSetup := setupDeviceTest(t)
 		device := deviceSetup.CreateDevice(t, "Test OPDS Device", "kobo", "opds-kepub-test")
-		bookID := createTestMediaItemID(t, setup.Server)
 
 		// Request KEPUB format
-		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID+"?format=kepub", nil)
+		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID1+"?format=kepub", nil)
 		httpReq.Header.Set("Authorization", "Bearer "+device.AuthToken)
 
 		resp, err := client.Do(httpReq)
@@ -250,10 +254,9 @@ func TestOPDSConversion(t *testing.T) {
 	t.Run("DownloadEPUB_DefaultFormat", func(t *testing.T) {
 		deviceSetup := setupDeviceTest(t)
 		device := deviceSetup.CreateDevice(t, "Test OPDS Device", "koreader", "opds-epub-test")
-		bookID := createTestMediaItemID(t, setup.Server)
 
 		// Request default format (no format parameter)
-		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID, nil)
+		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID2, nil)
 		httpReq.Header.Set("Authorization", "Bearer "+device.AuthToken)
 
 		resp, err := client.Do(httpReq)
@@ -267,10 +270,9 @@ func TestOPDSConversion(t *testing.T) {
 	t.Run("Download_UnsupportedFormat", func(t *testing.T) {
 		deviceSetup := setupDeviceTest(t)
 		device := deviceSetup.CreateDevice(t, "Test OPDS Device", "koreader", "opds-unsupported-test")
-		bookID := createTestMediaItemID(t, setup.Server)
 
 		// Request unsupported format
-		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID+"?format=pdf", nil)
+		httpReq, _ := http.NewRequest("GET", setup.Server.URL+"/opds/devices/"+device.ID.String()+"/download/"+bookID3+"?format=pdf", nil)
 		httpReq.Header.Set("Authorization", "Bearer "+device.AuthToken)
 
 		resp, err := client.Do(httpReq)
@@ -285,7 +287,7 @@ func TestOPDSConversion(t *testing.T) {
 // TestOPDSEdgeCases tests edge cases for OPDS endpoints
 func TestOPDSEdgeCases(t *testing.T) {
 	setup := setupTestServer(t)
-	_ = createTestMediaItemID(t, setup.Server)
+	_ = createTestMediaItemID(t, setup)
 	client := &http.Client{}
 
 	t.Run("Catalog_EmptyLibrary", func(t *testing.T) {