To use the Band data and To Key the amp you need to use the settings in Band Manager
In your setup you have overlooked 2 steps from what I can see
1) you need to disable the PA function button on the EESDR3 application display to do so set according to picture
Next open Band manage back up and now you will see the column outline for the PA function in the picture below.
Check the boxes for which bands you want the Keyline to trigger the Amp
You will not have a PA button on your front EESDR3 display it will be controlled according to what bands you have selected in the Band Manager section.
Also make sure for your AMP that the correct boxes for RTX and TX (external Control) are set correctly I'm not showing any of this in my setup because it is strictly a manually controlled amp- I do however use the PA function as outlined and no issues with pins 13/15 for Keyline triggering
To disable the PA function, go back to the first windows and unselect the PA (save by Band) this will give you an PA button back on the display but for an AMP that needs BCD it will not key the amp that I know of.
Try the above suggestions and let us know