Spring Cloud Gateway Exceeded limit on max bytes to buffer : 262144 Error

I uploaded a large JSON structure (a menu tree) from the frontend. When it reaches the gateway, it throws the following error:

DataBufferLimitException: Exceeded limit on max bytes to buffer : 262144

I’m using Spring 6 and Spring Cloud Gateway 4.

The first approach doesn’t work
spring:
codec:
max-in-memory-size: 10MB
cloud:
gateway:
httpclient:
response-timeout: 30s
connect-timeout: 10000

The second approach doesn’t work
@Bean
public WebFluxConfigurer webFluxConfigurer() {
return new WebFluxConfigurer() {
@Override
public void configureHttpMessageCodecs(ServerCodecConfigurer configurer) {
configurer.defaultCodecs().maxInMemorySize(10 * 1024 * 1024);
}
};
}

Start by reproducing the DataBufferLimitException with the large JSON menu tree and compare the two configuration approaches shown in the issue. Inspect Spring Cloud Gateway's codec and request-body handling entry points to determine which setting applies; done means the upload succeeds beyond 262144 bytes with a verified configuration or a documented defect.