AWS CodeDeploy not able to execute bash script

All Events Succeeded but flask app not starting

appspec.yml

    version: 0.0
    os: linux
    files:
      - source: /testServerRegadv.py
        destination: /path to folder in server/python

hooks:
  ApplicationStart:
    - location: scripts/start_server.sh
      timeout: 300
      runas: root
  ApplicationStop:
    - location: scripts/stop_server.sh
      timeout: 300
      runas: root

start_server.sh

#!/bin/bash
echo "In start server" >>results.txt 2> errors.log &

python /path in server/python/testServerRegadv.py > results.txt 2> errors.log &

stop_server.sh

isExistApp = `lsof -t -i:1515`
if [[ -n  $isExistApp ]]; then
    kill -9 $(lsof -t -i:1515)
fi

Also I am using code commit for storing the code and before pushing to aws code-commit I am executing chmod +x scripts/ * to make the scripts executable.