Issue Next.js 16 app crashing on Plesk with HTTP 499 despite Passenger configuration

[Aapklub]

I have deployed a Next.js 16 application on a Plesk server. The application is finally running after following guidance from this stack overflow posy: Deploy Next JS 14 on Plesk server

I also created a Passenegerfile.json in the root directory with the following configuration:

{
"environment": "production",
"max_pool_size": 20,
"min_instances": 1,
"max_requests": 8000,
"max_request_queue_size": 400,
"pool_idle_time": 0
}

However, the application continues to crash constantly, returning HTTP error 499. I'm tired of manually restarting the server to keep it running.

Here is relevant server log.

4184995/T39 age/Cor/CoreMain.cpp:1094: Checking whether to disconnect long-running connections for process 253380, application /var/www/vhosts/[sitename.com]/httpdocs (production)

Any help or suggestions would be greatly appreciated.