Issue with label_values Function in AdditionalScrapeConfigs in Managed Grafana

I am encountering an issue when trying to use the label_values() function to create a Grafana variable based on the instance label in my managed Grafana, which is connected to a Prometheus instance with additional scrape configs set.

Here is an excerpt of my values.yaml file:

prometheus:
  prometheusSpec:
    additionalScrapeConfigs: 
      - job_name: 'Spring Boot Application input'
        kubernetes_sd_configs:
        - role: pod
        relabel_configs:
        - source_labels: [__meta_kubernetes_pod_label_name]
          target_label: instance
          action: replace

As per the above configuration, the __meta_kubernetes_pod_label_name label is replaced with instance as expected. When I run this query:

sum by (url, httpStatusCode, outcome, application, namespace, instance)  (floor(increase(spring_cloud_gateway_verbose_seconds_count{application="$application", instance="test", namespace="my-namespace", url=~"https://$url.*", httpStatusCode=~"2..|3.."}[1m])))

I get a response as expected, such as:

{application="Datos Application", httpStatusCode="200", instance="test", namespace="my-namespace", outcome="successful", url="https://$url.*/assign"} 

However, when I try to create a Grafana variable with all "instances" using label_values(instance), it works perfectly in a k8s self-hosted Grafana instance (of the prometheus-community. But when I try the same in a managed Grafana instance, I get an error:

{status: "error", errorType: "Not Found", error: "Unsupported route. RequestId: 681c3231bdf241529433f2640c8f8a31"}

Can anyone please provide guidance on why this might be happening in the managed Grafana and how I can successfully create this variable? I think it related to the grafana version (prometheus-community vs grafana enterprise).

Thanks in advance for your help.