My auto-warn level is set to 30% (and has in the past been set to 20%). And invariably the phone is going on charge after the first time it asks me to put it on charge i.e. with an even lower charge level.
So, as neither of us experiences the problem but we have different charging strategies relative to “40%”, I don’t think that’s the difference.
Other factors to consider:
- whether one uses suspend (I don’t or at least I haven’t enabled it myself)
- Is there a firmware update for the touchscreen controller? (but it is not clear that that would affect the display itself) In any case I have not performed any update in respect of this firmware.