In other words, FD recently tested free floaters for the first time (they probably weren't even there before 2.1.05 due to a glitch or because we weren't meant to be able to find them yet) and discovered a problem with the audio after 6 minutes.
Possibly expected us to find free-floaters faster than convoys were found.
If so, it suggests their location is reasonably obvious, or easy to find at least.