Use digital theme show 502 Bad Gateway nginx

Use digital theme test download file show 502 Bad Gateway nginx, But using AWS Apache is normal

Nginx error logs is

error] 8075#0: *6 FastCGI sent in stderr: "PHP message: PHP Warning: ltrim() expects parameter 1 to be string, object given in /www/wwwroot/domain.com/wp-includes/formatting.php on line 4309" while reading response header from upstream, client: ***.215, server: domain.com, request: "GET /checkout/ HTTP/1.1", upstream: "fastcgi://unix:/tmp/php-cgi-74.sock:", host: "domain.com", referrer: "http://domain.com/downloads/123/"

php error logs is

(request: "POST /index.php?payment-mode=manual") executing too slow (38.937964 sec), logging
[12-Nov-2020 07:59:52] NOTICE: child 9321 stopped for tracing
[12-Nov-2020 07:59:52] NOTICE: about to trace 9321
[12-Nov-2020 07:59:52] NOTICE: finished trace of 9321
[12-Nov-2020 08:01:02] WARNING: [pool www] child 9321, script '***/domain.com/index.php' (request: "POST /index.php?payment-mode=manual") execution timed out (108.949547 sec), terminating
[12-Nov-2020 08:01:02] WARNING: [pool www] child 9321 exited on signal 15 (SIGTERM) after 190.038390 seconds from start
[12-Nov-2020 08:01:02] NOTICE: [pool www] child 9596 started

Cpu 2 core+4G ram now ram is 1800m/3944m Nginx 1.18.0+MySQL 5.6.49+PHP7.4

Somebody can help me thanks a lot T_T