No problem,
It didn’t take long for me to find a solution , it was a missing PID file required for the service to run.
Issue was fixing by adding the following line to the configuration file under the “processManagement”:
pidFilePath: /var/run/mongodb/mongod.pid
Followed by systemctl daemon-reload, and reverting my TimeoutStartSec to 60seconds to make sure it is working after the given time. Hopefully it will help someone