I mean, there's a reason I said it would be rooted in a tiny irrational part of Renxiang's mind, that she doesn't have a good handle on because of her (non)emotional trauma and it only more recently starting to grow as her companions have faced challenges and dangers. There's potential for symmetry with another experience we know she went into with a deeply held sense of trust in her companion; meeting failure or setback while your companion is less directly engaged in helping you than you expected, than you yourself had just recently committed yourself to them in this situation, is the kind of thing that can trigger an unfair echo of hurt.
The tiny irrational part of Renxiang's mind doesn't tell her that people should be helping her more than they are, the tiny irrational part of Renxiang's mind tells her that she herself should be doing more, preferably everything, preferably personally, so she doesn't ever need any help at all and no-one ever gets hurt or wants for anything when she's around.
I know it can be more than one thing, but in this situation I'm pretty sure the balance falls towards the possibility of Renxiang having to shut up her internal brain asshole if Ling Qi DID interfere with the duel.
If anything, considering Ren-Ren came here to support and cover Ling Qi in the first place, her turtling up and successfully not-needing-to-be-rescued might just be the necessary option that DOESN'T trigger irrational microresentment of the "please stop making it so hard for me to be the protector" variety.
"Your companion is less directly engaged in helping you than you expected" <= I think this is where the disconnect is. I do not believe Renxiang expects or wants Ling Qi to interfere in what Ling Qi has identified as a duel, presumably not without reason. If she starts actually losing, sure, she'll expect Ling Qi to bail her out at the last moment, but we all know that if that happens Ling Qi WILL do that.
Letting her get battered on her own for as long as she can hold out will factually be psychologically easier on her.
Renxiang's damage, so to speak, is not in being underprotected by subordinates. It's in learning that she needs to prove herself and be perfectly perfect at all times to earn her mother's affection/protection/help. Servants, guards and whatnot she's always had aplenty, she just learned that she wasn't
really good enough for them unless she bled herself out to the last tiniest drop.
She'll feel better about giving more than she got, not the other way around, I'm rather confident.