Why did i get GCS Failsafe?

Hello all,

i send drone to a mission and it RTL’d with GCS failsafe ,

Why did that happen ? i have log attached :

At the first part of the flight i only had mission planner connected via rdf telemetry then i also open the QGC from with in herelink , it sounds the rdf telemetries disconnected ?

Thank you for your time,
Best!