It’s frustrating I know.
When I got my serial Hi Pro year’s ago I had a similar hold up as you. My issues were driver related and USB to serial cable conversion. It took three different cables and drivers to get the Hi Pro to function. That’s been 10 years ago.
You might double check updates for your computer and also the Hi Pro.
Following this thread it sure looks like the cables from your Hi Pro to the aids are not communicating some how. Thinking out loud, your Oticon software sends a signal to the Hi Pro which goes to the aids then back the way it came. Somewhere in that sequence the left and right lights should light. Could be the Oticon program not sending the signal, Hi Pro not relaying to the aids, bad wiring or connection. With both aids doing the same thing it seems it would be the Oticon software or the Hi Pro, something common to both aids.
PVC is good at this stuff. You have good help.
You’re ignoring this member’s posts.