Cookie consent bar doesn't save

I have added the Cookie Consent Bar for Hydrogen (Analytics consent and customer privacy) to a client’s site and it refuses to work on the primary site domain.

On localhost during testing everything works great. The cookie bar loads, I can set what I want tracked and the cookie is updated and the bar gets hidden on subsequent page loads. Once the code gets deployed to production the ‘cookie saving’ never works. I have tried multiple suggestions from Shopify, all with no success. Their tech team did mention that since we have some extra code in session handling (using multipass) it could be causing an issue, however that seems off since everything works fine in the local environment.

Any suggestions on how to fix or what to look at for potential root causes would be greatly appreciated.