Hi Syed,
it could be SELinux if still enabled.
If yes, you should also apply the proper context to you moodledata folder:
# SELinux - Allow httpd to read/write to the moodledata directory
semanage fcontext -a -t httpd_sys_rw_content_t "/var/www/moodledata(/.*)?"
restorecon -R /var/www/moodledata
Ref.: http://blog.mrverrall.co.uk/2015/10/moodle-on-centos-and-red-hat-7.html
Besides, keep care of properly setting user permissions even when configuring the Moodle cron: https://docs.moodle.org/34/en/Cron#Finding_the_right_place_to_put_the_command
HTH,
Matteo