Today I upgraded my entire website from Moodle 2.9.9, Joomla 3.7.2, and Joomdle 1.0.7 to Moodle 3.3.2, Joomla 3.7.5, and Joomdle 1.1.3 and now single sign on is not working. Everything worked 100% before upgrade. All other functions except single sign on work, I can manually sign on to Moodle. I can provide access to backend if needed.
PHP version is 7.1