Uncovering the mysteries of JSON files in UI7

I’m having an issue with the json file for devices controlled by the RFXtrx plugin I maintain. These UI7 json files have been a mystery to me and a lot of others in the past. My issue right now is with trying to create a scene to operate one of these devices. The json file defines 5 buttons in two rows; 3 on top and 2 below. When creating the scene at the point where the button (action) to trigger is selected, the top left button is already selected. Selecting any other button on that row does select that button but does not de-select the one to the left. In fact each of the three buttons can be selected and none can be de-selected. The two buttons on the second row seem to almost work as they should. Initially neither is selected. Selecting one and then the other will de-select the previous one. But once one is selected in the row of two, one is always selected. This goes along with selecting any button in the row of three causes it to always be selected - not de-selecting any other.
See the attached if necessary
D_WindowCovering2.zip (1.6 KB)