Can't Edit Unlocked Cells in Embedded Sheet (Calculator)

Can't Edit Unlocked Cells in Embedded Sheet (Calculator)

I've had an embedded Sheet for several years that allows visitors to my website to input their info and see the results (calculator type application). It is understood that the changes aren't saved on my original copy.

I've made some updates to the Sheet (actually created a new Sheet) and have locked the cells that have calculations -- but the unlocked cells can't be changed on the web screen for some reason. The Sheet is not locked/protected.

Any suggestions? I'm pulling my hair out trying to figure this out.

Thanks!