Update - We've noticed some inconsistencies in Send To Messenger button and Checkbox plugin not working correctly on Safari 12 (possibly older Safari versions as well): Opt-In Messages might not be sent to Messenger after interacting with the button.

We're continuing to monitor the situation - further updates will be posted in this incident.
Dec 11, 07:13 PST

Update - We can see that Messenger plugins are now working on Safari 12.
We'll be monitoring the situation for some time before closing this incident.
Dec 7, 02:06 PST

Monitoring - Support for Messenger plugins on Safari 12 has been temporarily disabled by Facebook. This affects web growth tools that use Send to Messenger button or Checkbox Plugin only when the user is using Safari 12.

Facebook team is actively working on addressing this. Unfortunately, they do not have publicly available ETA on this feature.

Other Safari versions should be fully supported.

ManyChat team has filed a bug report with Facebook and you can see live updates here: https://developers.facebook.com/support/bugs/2236443336620367/

We will update this incident with further information as soon as we get more info or ETAs.
Nov 2, 14:50 PDT