Welcome to the forum! Many have had problems with the Axxera radios and replaced them with another brand. Some went with Jensen or Pioneer. Check out Crutchfield, they have great phone customer service.
The problem as you described is almost surely a connection. Did you try unplugging the cables one by one and spraying with a electronic cleaner like CRC? I would go back and do that before shopping for a replacement.
If all else fails, read the directions!!