Your keyboard wiring cannot be wrong based on what you've reported.
If software says it's a hardware problem, which I suspect is true, then the problem must be in the firmware.
Have you ever updated the firmware? That is, are you still using the firmware that was installed when the keyboard was in possession of Pine 64?
(By the way, the difference between the keyboard in the PBP and the keyboard for your Interact 8080 is a layer of hardware abstraction. It is achieved by a microprocessor inside the keyboard unit. The famous analogy is the 6502 hidden inside Amiga keyboards. But most common keyboards since long before that had a microprocessor in the keyboard for this purpose.)
If software says it's a hardware problem, which I suspect is true, then the problem must be in the firmware.
Have you ever updated the firmware? That is, are you still using the firmware that was installed when the keyboard was in possession of Pine 64?
(By the way, the difference between the keyboard in the PBP and the keyboard for your Interact 8080 is a layer of hardware abstraction. It is achieved by a microprocessor inside the keyboard unit. The famous analogy is the 6502 hidden inside Amiga keyboards. But most common keyboards since long before that had a microprocessor in the keyboard for this purpose.)