ACER Swift 3 SF314-41 [STRONGBOW_PK 18848-1] - Not see or charge battery

Hi

I have this laptop that does not see or charge the battery, it will power on from the mains fine.

I have tried 2 other batteries and symptoms are the same.

I have measured the 5 mosfets all seem good, apart from the 3 involved with the battery/charging have a very big difference when the battery is connected to when it is not. Measurements are below, ( readings in brackets are when battery NOT connected).

PU4408
D-S = 3.9 M ohm
D-G = 20 M ohm
S-G = 4.1 M ohm

PU4401
D-S = 3.9 M ohm
D-G = 25 M ohm
S-G = 4 M ohm

PU4402
D-S = 85 k ohm (550k)
D-G = 28 M ohm (2.1 M ohm)
S-G = 1.7 M ohm

PQ4403
D-S = 59 k ohm (2.8 M ohm)
D-G = 280 k ohm (3 M ohm)
S-G = 156k ohm

PQ4404
D-S = 40 k ohm (2.8 M ohm)
D-G = 220 k ohm (3 M ohm)
S-G = 175 k ohm

all the resistors around the IC measure good,
Pin15 (BATPRES) measures low when battery is connected and high 3.3v when not connected which is correct according to datasheet.

I have also changed the charging IC PU4403 (BQ24781) for BQ24780S which is known compatible and still no change.

both PD4404 and PD4405 measure 0.279 forward and OL reverse, and PR4424 and PR4425 both measure 10ohms.

SDA and SCL on the battery connector, both have continuity to PU4403 and both lines measure about 35k ohms

I hope somebody can help
Thank you