Visual Basic DataRepeater Controls Disappear

Question

When I make any attribute changes to any control on my form, all of the controls within all DataRepeaters disappear within Visual Studio and when running the app. The DataRepeaters are the blocks with the header "Region A B W" and the area starting with the label "# Section Seq".

Form before making a change:

Form after making a change:

I would very much appreciate suggestions on how to resolve this.

Thanks, Tracy