nohup ends when I close the SSH terminal and doesn't show up on ps/job when running

I have an AWS EC2 Ubuntu 20.04 instance, accessed via puTTY SSH. Running a Python process via OpenMPI through the following command **on non root**: > nohup mpirun python3 job.py When the shell is open it runs normally. Even though using ps and job doesn't show the process I can see via the nohup.out and the changing file system that it's working even hours after it runs. When I close the shell the nohup process ends. I should probably also note that when I run the nohup command above I cannot enter any more input (the cursor becomes blank). So when I ran ps and job above I had to open a second shell. I never used nohup before and assume this is abnormal. I investigated the nohup.out file for errors and found nothing written. So TLDR: 1. Closing the SSH instance (puTTY) ends the nohup process 2. ps and job don't list the nohup process even though I know it's running *I can answer any more questions if needed*