Entity Form not moving to the next step

Hi

I'm using the Custom Portal with a Dyn 365 instance. I've created a new web page, and associated that with a brand new entity form that's using a CRM form from a custom entity.

On the portal, I checked the box to Auto Generate Steps from tabs of the CRM form. The form has 4 tabs.

It works fne for the first and second tab, meaning that the first tab loads on the web page, and when I click next, it moves to the second tab. However, from there, even though I hit next, it's that same second tab with the data that keeps coming back.

I've emptied the cache, resarted the portal a couple of times, published customizations...  I don't know where to look for anymore!

Any thoughts?

Thanks!