Lightsail timing response very slow

Hello.

From the shared image, it appears that the CPU usage has exceeded the baseline throughput and used up the burst credits.
In other words, your Lightsail is currently running at less than its baseline throughput, causing your website to stop or slow down.
https://docs.aws.amazon.com/lightsail/latest/userguide/amazon-lightsail-viewing-instance-burst-capacity.html

There is a possibility that Lightsail's specifications are insufficient, so why not consider upgrading the specifications?
Changing your Lightsail plan requires creating a snapshot of your current instance and creating a larger instance from the snapshot.
https://repost.aws/knowledge-center/change-lightsail-plan