I replied to your email but thought the reply may be of interest to other people so am posting it here.
I think what you highlight is by design. On the Drop Data page the main property is the drop. You start with the drop and then you assign the valve and the times. The large label to the left indicates the drop; D1, D2, D3, etc. In the graph the display is based around the valves. I realize this is the opposite to the drop data but it fitted with how I was working when I created the app. My work flow has changed somewhat since though.
I have played with changing how the apps work but haven’t found a nice solution (one I was happy with) yet. The closet I have got is to add a label to the line in the graph showing the drop number but this only works when the drops are certain sizes and the graph is at certain scales.
Just had an idea, an easy solution may be to add a key showing what colours represent what drops.