I have 4 choices and the control is configured to use 4 columns across then down. Each radio button control renders immediately next to the text label for the previous control with no spacing.
I had the same problem but with Nintex forms Sharepoint on-prem.
Found a workaround by adding at the end of eah choice value (which is a space in HTML)
Not very elegant but does the job for me and didn't want to mess with custom CSS.