Lumen - createPdoConnection is too slow

I have an Api Service using Lumen 8 with a quite a lot of traffic, somewhere around 350 requests/second and when I get closer to this value, I'm starting to have response time issues.

I'm monitoring this app using NewRelic and I noticed that the problem appears with the PDO Connector. The response time varies between 2 and 20 seconds to create the pdo connection.

We're using AWS: EC2-server: c5.4xlarge , php8 Database: db.m5.8xlarge, MariaDB 10.6.

what would be the problem?