It seems that if you have a team that has Admiral Raddus and Jyn Erso on it, Jyn cannot be instantly defeated. This is because Jyn gains "uniqueabilty_admiralraddus01_jyn_cannot_be_defeated" as a health limit. Instant defeats, such as the one that The Mandalorian gains, do not dispel this, but they do dispel others such as "leaderability_quigonjinn_no_defeat_effect_jedi", which is what Qui-Gon uses to keep his Jedi alive.
The main reason I make this report is that it is inconsistent. Raddus’s ability says
While Admiral Raddus is active, Jyn Erso can't be defeated.
and Qui-Gon says
At the start of battle if there are no Galactic Legends and all allies are Jedi: All other allies…can't be defeated while Qui-Gon Jinn is active.
Having a consistent definition for "can’t be defeated" is what I ask.
Edit: I didn’t do my homework very well, apparently Dark Side Rey and kind of CT-5555 Fives have the same issues