I’m hoping you can help I have configured a custom domain to send data to GTM. However when I try and test the events in Google tag manager preview the events are showing “Successfully fired” however they are “Unknown Tag Type” and the data values are blank.
Preview makes periodic calls to the server to render whatever has happened in your particular preview session, as such there are moments when only part of the info related to any given request/tag has loaded. You should just wait a bit, or send some more events and eventually you’ll see actual status/info of tags.
At least this is what I assume is your problem, ideally please sprinkle more information on top so that community can better help you.