devtrackers.gg
I have occasionally had that mf just despawn himself mid mission and insta fail it. Not fun considering how much of a slog it is.
Hiho!
We recently changed Defense Operatives to make it so they can't get ragdolled anymore:
Fixed auto-failing the mission if the Defense Operative were to ragdoll out of the playable area. This bug was most commonly experienced in an Archon Hunt mission with Chipper.
https://forums.warframe.com/topic/1414770-update-37-koumei-the-five-fates/
This should have fixed any issues for Defenses with a mobile Operative failing without visible reason.
Cheers!