Empty values in drop-down selection

I have a number of drop-down selections as part of my form.

With 4 selections (A, B, C, D) for example, I want to give A the empty value and B, C, D as positive selections. So I tick the ’empty value’ box for A and untick for B, C, D.

However, all four keep ticking themselves automatically, even after saving as unticked. This means all my form submissions are showing no selection, regardless of which selection has been made.

Is this a glitch or am I missing something? Thank you.

https://ww.wp.xz.cn/plugins/form-maker/