I think the GTM integration isn't very smart at enabling session replay after initialization.
It looks like your tag is set to require analytics_storage consent before it fires. Is it possible in production, that consent isn't being granted by the time that tag fires?
Great. In the mean time, you'll probably want to update your GTM tag's Initialization section to specify Initializtion Options as Set options manually, then set Option keypersistence to cookie
Greetings, friends! I just integrated Mixpanel into terraformation.com using Google Tag Manager, and it was really easy. Thanks for making this such a simple setup!
For terraformation.com/plant , we use a subdomain plant.terraformation.com to host an iframe containing payment UX. I noticed Mixpanel + Google Tag Manager was sending different Distinct IDs for the outside (parent) HTML and the inner (iframe) HTML, even though the documentation says that subdomain tracking should work by default.
I tracked this behavior down to https://github.com/mixpanel/mixpanel-gtm-template/pull/18 which landed in September, It changed the default persistence to localStorage for Google Tag Manager users.
This breaks subdomain tracking, which really surprised me. Explicitly changing persistence back to cookie solved the problem for me.
