Improve logging in AuthenticationWebFilter

Closes #14091

web/src/main/java/org/springframework/security/web/server/authentication/AuthenticationWebFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -125,7 +125,7 @@ public class AuthenticationWebFilter implements WebFilter {
 			.flatMap(
 					(authentication) -> onAuthenticationSuccess(authentication, new WebFilterExchange(exchange, chain)))
 			.doOnError(AuthenticationException.class,
-					(ex) -> logger.debug(LogMessage.format("Authentication failed: %s", ex.getMessage())));
+					(ex) -> logger.debug(LogMessage.format("Authentication failed: %s", ex.getMessage()), ex));
 	}
 
 	protected Mono<Void> onAuthenticationSuccess(Authentication authentication, WebFilterExchange webFilterExchange) {