I changed a field to be size: Large instead of Medium. After this I noticed that there was a wide gap between the two columns. I switched the field size back to Medium but the gap didn't go away.

I also added a subform, perhaps that had an impact? 

I've opened the form up for Zoho to edit/help. Is there anyone who can look into this form width issue? 

Here's a screenshot of my form next to what a normal form would look like: