Laravel queue fails to run properly in supervisor

I am using redis queue for sending emails in my code. Redis is working fine but supervisor is not working as expected. I was using numprocs=1 but once an email is triggered the next email is not sent until I restart supervisor and submit triggered again. I changed the value to numprocs=8 and it was working fine for many times until this happened again. The artisan queue command was still running in the background but the email was not sent on the submit form and nothing was processed in "ecap_phase2_stg_api_queue.out.log". If I restarted supervisor the email will be sent when I hit submit again. Now, I am running the command "php artisan queue:work --timeout=1000 --sleep=3 --tries=3" in a tmux session to stay running in the background.

[program:laravel_queue-stg-api]
process_name=%(program_name)s_%(process_num)02d
command=php /var/www/stg-api/artisan queue:work --timeout=1000 --sleep=3 --tries=3 --daemon
autostart=true
autorestart=true
numprocs=8
redirect_stderr=false
stdout_logfile=/var/www/stg-api/storage/logs/queue/ecap_phase2_stg_api_queue.out.log
stderr_logfile=/var/www/stg-api/storage/logs/queue/ecap_phase2_stg_api_queue.error.log

What is the cause of this failure?

via Chebli Mohamed