In order to run script at startup, using crontab is fairly the best way.

Have you run crontab -e as superuser ? (with sudo) If not you must do so because only superuser can manage GPIO :

sudo crontab -e

If you did, why don't you try capturing what happens in an error lo like so :

@reboot [command] > actions_log.txt

Also, does crontab work at all for you  ? You can do as follows to check :

@reboot touch test_file.txt

And see if the file is created or not.

In order to run script at startup, using crontab is fairly the best way.

Have you run crontab -e as superuser (with sudo)?

If not you must do so because only superuser can manage GPIO :

sudo crontab -e

If you did, why don't you try capturing what happens in an error log like so :

@reboot [command] > actions_log.txt

Also, does crontab work at all for you? You can do as follows to check :

@reboot touch test_file.txt

And see if the file is created or not.