RHEL service works when starting manually, but won't start automatically when enabled for reboot. (main process exited, code=exited, status=126/n/a)

I created a linux service to start a shell script when the server (re)starts. While testing my server I saw that the service is able to start when I do it manually but won't start when I enable it with "systemctl". What is causing this? My logs: **systemctl status script.service** script.service - name Loaded: loaded (/etc/systemd/system/scriptname.service; enabled; vendor preset: disabled) Active: failed (Result: exit-code) since Mon 2024-03-04 15:39:34 CET; 3min 45s ago Process: 1303 ExecStart=/usr/local/bin/scriptname.sh (code=exited, status=126) Main PID: 1303 (code=exited, status=126) Mar 04 15:39:34 sar systemd: Started ######. Mar 04 15:39:34 sar systemd: scriptname.service: main process exited, code=exited, status=126/n/a Mar 04 15:39:34 sar systemd: Unit scriptname.service entered failed state. Mar 04 15:39:34 sar systemd: scriptname.service failed. **journalctl -u servicename.service | tail -n 50** -- Reboot -- Mar 04 15:39:34 sar systemd: Started #####. Mar 04 15:39:34 sar systemd: scriptname.service: main process exited, code=exited, status=126/n/a Mar 04 15:39:34 sar systemd: Unit scriptname.service entered failed state. Mar 04 15:39:34 sar systemd: scriptname.service failed.