A fix has been implemented and we are monitoring the results.
Posted Jan 24, 2019 - 02:35 PST
After opening the Customer Chat widget on a site, it' can't be closed by clicking on the X button. The problem is on Facebook's end and it affects all active Customer Chat widgets. Facebook is currently investigating the matter. For more information, check Facebook's bug report: https://developers.facebook.com/support/bugs/522187728275011