Tanqueray

So I'm trying to unplug the connector from the boost pressure sensor so I can replace the sensor, but for the life of me, I cannot disconnect the connector from the boost pressure sensor.

There is a grey plastic tab, that I pull out, away from the connector towards the sensor side, which should loosen the connection and I can just simply pull out the wire... But it will not budge!!!

I read somewhere I need to first pull out the grey tab and as I pull the connector out from the sensor, I need ti slightly press the grey tab in... I tried that too and that still doesn't work!!!

Does anyone have any tip on how to remove these connectors from the sensors?