Hi Francky,
The radar locks are currently available only to FC3 aircraft piloted by the local player. So, if you are flying the F/A-18 for example or you are watching a Su-27 from ANOTHER player or an AI, you will not get them…
This is a limitation of the telemetry API of DCS World. I am thinking of a workaround, if this is successful, I will implement it in a revised version of the exporter.