Other than a specific fault, the battery saver + found in PHEVs has issues. It actually increases "vampire" loads. Below is some quoted text and a chart from an Ioniq post - they have the same issues with PHEVs.
Interesting information, thanks for posting that.
This thought seems kind of a stretch, but I wonder if it's really BS+ causing the observed drain, or if the sleep logic behaves differently when it knows that BS+ is enabled.
The way I drive my PHEV (the ICE might not run for a couple of weeks at a time), the BS+ is probably necessary. The thing is, even when I do run the ICE for three or four hours of driving, if I don't see the alert that BS+ ran the next day when I start the car, I'll usually see it two days after running the ICE.
I do wish that Kia had thought to include in addition to BS+ the mechanical switch in the PHEV that they provided to HEV owners The idea that you could have a depleted 12V battery, a fully charged traction battery, but no way to boost the 12V from the traction because BS+ already ran three times and then gave up, seems to reflect an engineering decision that could have been better thought out. If there's some technique for inducing BS+ to come on again after it's timed out, I'd love to know, but my guess is that the logic is driven by the computer running on the 12V battery and by the time you notice a problem, the computer probably won't run. This is where the mechanical switch is likely to have a significant advantage.