Playwright webserver is working fine with port 4200 but not working with other open ports

Playwright webserver is working when I have port 4200 like http://localhost:4200 but it is not working with other open ports like http://localhost:5151

This works { testDir: './e2e-tests', fullyParallel: true, forbidOnly: false, retries: 0, workers: undefined, reporter: 'html', use: { baseURL: 'http://localhost:4200', trace: 'on-first-retry' }, projects: [ { name: 'chromium', use: [Object] } ], webServer: { command: 'npm run start -- --port 55756', url: 'http://localhost:4200', timeout: 120000, reuseExistingServer: true } }

This does not work { testDir: './e2e-tests', fullyParallel: true, forbidOnly: false, retries: 0, workers: undefined, reporter: 'html', use: { baseURL: 'http://localhost:55756', trace: 'on-first-retry' }, projects: [ { name: 'chromium', use: [Object] } ], webServer: { command: 'npm run start -- --port 55756', url: 'http://localhost:55756', timeout: 120000, reuseExistingServer: true } }

Can anyone help why is that happening? I'm using 1.35.1 or 1.36