diff --git a/openvidu-test-e2e/src/main/java/io/openvidu/test/e2e/OpenViduTestE2e.java b/openvidu-test-e2e/src/main/java/io/openvidu/test/e2e/OpenViduTestE2e.java
index d845f7842..4dbb65190 100644
--- a/openvidu-test-e2e/src/main/java/io/openvidu/test/e2e/OpenViduTestE2e.java
+++ b/openvidu-test-e2e/src/main/java/io/openvidu/test/e2e/OpenViduTestE2e.java
@@ -14,10 +14,10 @@ import java.security.KeyManagementException;
 import java.security.NoSuchAlgorithmException;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.regex.Pattern;
 
 import javax.net.ssl.SSLContext;
@@ -116,8 +116,8 @@ public class OpenViduTestE2e {
 	protected static final CommandLineExecutor commandLine = new CommandLineExecutor();
 	protected static final String RECORDING_IMAGE = "openvidu/openvidu-recording";
 
-	protected Collection<BrowserUser> browserUsers = new HashSet<>();
-	protected static Collection<GenericContainer<?>> containers = new HashSet<>();
+	protected Collection<BrowserUser> browserUsers = ConcurrentHashMap.newKeySet();
+	protected static Collection<GenericContainer<?>> containers = ConcurrentHashMap.newKeySet();
 
 	protected static RoomServiceClient LK;
 	protected static IngressServiceClient LK_INGRESS;
@@ -512,18 +512,22 @@ public class OpenViduTestE2e {
 		return browserUser;
 	}
 
-	private static synchronized boolean setupBrowserAux(BrowserNames browser, GenericContainer<?> container, boolean forceRestart) {
+	private static final Map<BrowserNames, Object> browserSetupLocks = new ConcurrentHashMap<>();
+
+	private static boolean setupBrowserAux(BrowserNames browser, GenericContainer<?> container, boolean forceRestart) {
 		if (isRemote(browser)) {
-			String dockerImage = container.getDockerImageName();
-			String ps = commandLine.executeCommand("docker ps | grep " + dockerImage, 30);
-			boolean containerAlreadyRunning = container.isRunning() || !ps.isBlank();
-			if (forceRestart && containerAlreadyRunning) {
-				container.stop();
-			}
-			if (!containerAlreadyRunning) {
-				container.start();
-				containers.add(container);
-				return true;
+			synchronized (browserSetupLocks.computeIfAbsent(browser, b -> new Object())) {
+				String dockerImage = container.getDockerImageName();
+				String ps = commandLine.executeCommand("docker ps | grep " + dockerImage, 30);
+				boolean containerAlreadyRunning = container.isRunning() || !ps.isBlank();
+				if (forceRestart && containerAlreadyRunning) {
+					container.stop();
+				}
+				if (!containerAlreadyRunning) {
+					container.start();
+					containers.add(container);
+					return true;
+				}
 			}
 		}
 		return false;
diff --git a/openvidu-test-e2e/src/test/java/io/openvidu/test/e2e/OpenViduTestAppE2eTest.java b/openvidu-test-e2e/src/test/java/io/openvidu/test/e2e/OpenViduTestAppE2eTest.java
index 3737d1ea0..03eadad1e 100644
--- a/openvidu-test-e2e/src/test/java/io/openvidu/test/e2e/OpenViduTestAppE2eTest.java
+++ b/openvidu-test-e2e/src/test/java/io/openvidu/test/e2e/OpenViduTestAppE2eTest.java
@@ -1338,7 +1338,7 @@ public class OpenViduTestAppE2eTest extends AbstractOpenViduTestappE2eTest {
 		final java.util.concurrent.atomic.AtomicLong subscriber1920AtMs = new java.util.concurrent.atomic.AtomicLong(
 				-1);
 
-		final String publisherBrowser = subscriberBrowser == "chromeTwoInstances" ? "chromeTwoInstances" : "chrome";
+		final String publisherBrowser = "chromeTwoInstances".equals(subscriberBrowser) ? "chromeTwoInstances" : "chrome";
 
 		Future<?> task1 = executor.submit(() -> {
 			try {
@@ -3590,13 +3590,14 @@ public class OpenViduTestAppE2eTest extends AbstractOpenViduTestappE2eTest {
 				Assertions.fail(errMsg);
 			}
 		} finally {
-			// Close dialog
-			user.getWaiter().until(ExpectedConditions.presenceOfElementLocated(By.cssSelector("#close-dialog-btn")));
-			this.waitForBackdropAndClick(user, "#close-dialog-btn");
+			// Best-effort close of the info dialog
 			try {
-				Thread.sleep(500);
-			} catch (InterruptedException e) {
-				e.printStackTrace();
+				if (!user.getDriver().findElements(By.cssSelector("#close-dialog-btn")).isEmpty()) {
+					this.waitForBackdropAndClick(user, "#close-dialog-btn");
+					Thread.sleep(500);
+				}
+			} catch (Exception e) {
+				log.warn("Best-effort info-dialog close failed (ignored): {}", e.getMessage());
 			}
 		}
 	}