High gate pin current leakage on a p channel mosfet
My suspicion is that Q35 shows leakage. Let's look in the datasheet of the YJL3400A.
It states: Zero gate voltage drain current = 1 uA max
So if it was 1 uA through 470 kohm you'd get 470 mV, so 0.3 V is perfectly feasible.
I suggest replacing Q35 with an NMOS that has a lower leakage current!
That YJL3400A has a very low \$R_{DS,on}\$ which is nice if you want to switch large currents but often means such a MOSFET has a relatively high leakage current. Here you don't need that low \$R_{DS,on}\$ so you can use a MOSFET designed for small currents but a low leakage current.