Jenkins UI suddenly became super slow after I rebooted my EC2 instance

Recently, I faced a weird issue —
Jenkins UI suddenly became super slow after I rebooted my EC2 instance.

At first, I blamed the browser cache and even tried switching from Chrome to Brave to MSEdge.
But guess what? The real issue was deeper.

After debugging, I realized the problem was due to EC2’s dynamic IP.
When the instance rebooted, its public IP changed — but Jenkins was still referencing the old IP stored in a config file.

Fix?

Step1: I located the IP inside:
/var/lib/jenkins/jenkins.model.JenkinsLocationConfiguration.xml

Step 2: Updated it with the new IP

Step 3: Restarted Jenkins
And boom — everything worked like a charm.

Lesson learned?
If you're hosting Jenkins (or any service) on AWS EC2, use an Elastic IP or automate the IP update in your setup