I just wanted to report 3 issues I am having with the CB Conditional plugin:

1. For some reason certain fields must be assigned to the Portrait tab otherwise step by step registration is not possible. For example the password field: If it is assigned to the portrait tab, it works. It is assigned to the contact tab, clicking next in the registration form, the validation message pops up telling that the field is required.

2. If such a field is set to NOT required, the popup message tells it is required when clicking on "Next".

3. Turning off validation per step in the config, leads to completely turning off step by step registration. All fields are displayed in one form again.

Ok. I am using the latest release and disabling validation disables step by step. In that case the entire layout falls back to the original form layout with everything on one page. Enabling validation does make it work again

That was quick. Great. Now the situation is as follows:

1. Disabling validation works now. It does no longer break the form and no more validation popus.
2. However, there is still the issue regarding certain fields assigned to certain tabs. For example: I have 2 tabs, portrait and contact. When I assign the username field to the portrait tab, step-by-step works. The field shows up in the first tab of the registration page and I can click to the next tabs.
When I assign the username field to the contact tab, the field does not show up on the first tab (which is correct), but when I try to get to the next tab, the validation message pops up telling me to fill out username. Of course I cannot do this, because the username field has been assigned to the second tab which I cannot select.
Only turning validation off solves this for now as this is the only way to switch to the second tab.
It is weird, that this behaviour does not show for all fields. I have experienced this for the username field, the password field and a customs field of mine. Other fields can be assigned anywhere without showing this weird behaviour.

I hope this extensive description helps to find the solution for this.