Apache SSL renewal keeps using old certificate

I have a website using Apache that runs on a GCP VM instance with a Google load balancer. In total, I have 3 servers

I have changed the SSL certificate in the Google load balance configuration.

What I have done so far to check are

1. using gcloud command gcloud compute target-https-proxies list to check if the latest SSL was installed or not
2. Running gcloud command gcloud compute target-https-proxies update PROXY_NAME --url-map=URL_MAP to update with latest proxy configuration

And everything looks good, but from the browser, I still can see that the website uses an old SSL certificate.

I also tried to use another browser or the online tool that John Hanley suggested, but still, it shows as the old certificate.

any idea how to solve it?