I came upon a stumbling block a few days ago during an effort to re-engineer some old InfoPath forms into Nintex for O365 forms. The culprit was the Choice Field Control. It does NOT work the same in both applications.

Initial Control Display

I got this when I dragged and dropped the choice control onto the Nintex Form for O365 canvas - and was initially stumped. Where are my choices??

Looking at the control's properties, I knew it had more than one choice.

So, I figured that it must be a sizing thing - and I was correct. I was able to see all of the choices by re-sizing the boundaries of the control.

Vertical vs. Horizontal Layout

That's great, but I wanted the layout of the choices to be horizontal, not vertical. That was easy in InfoPath. Each option was separated by a carriage return. Simply deleting the carriage returns between choices produced a horizontal line of choices. Unfortunately that's NOT the case with Nintex forms. In Nintex, you have to do a few more steps.

1. On the form canvas, double-click the Option control to open the Control Settings dialog window.
2. From the Arrange choices drop down in the General Section, select Across then down.
   
   
3. Update the Number of columns value to match the number of options that are in the control. In my example, I set it to 3 - because I have three options.
   
4. Click Save.
5. Re-size the control as needed.

Now I the control is formatted the way I want. It's certainly not as easy as deleting carriage returns, but its not too difficult to switch between the vertical and horizontal orientation of a Choice control in Nintex Forms for O365.

I hope this article helps reduce your stumbling blocks when re-engineering from InfoPath to Nintex.