Interesting. Is this a quality control problem, or manufacturing defect with new units? Is that picture from inside a C23?This is an example of what @Vaklin is referring to.
View attachment 27630
If you look at where the co-ax cable meets the solder filet the shielding is broken and makes poor contact. This results in a high SWR (standing wave ratio) and intermittent loss of continuity as cable gets flexed.
Experimentation with different antenna and ground station can help identify the problem area. Camera, antenna on ground station, or WiFi card in the ground station.