This started happening for our customers on 10th September.
When an issue is opened from a board in a popup there is a web panel with our addon. From it, user can open another dialog - the iframe is added to the page and all the resources are fetched but the callback passed as an argument to AP.dialog.getCustomData is no longer called. There were no changes on our side and it was working fine for a long time. Also, it’s working fine when issue is opened in a sidebar or directly in a separate tab.
Does anyone else encountered that problem? Is this a regression in Atlassian Connect?