Won't be Amal valve if this was the case you woulden't be able to run that boost at all.

The amal valve should click when ignition is switched on/engine running. If you disconnect/connect the plug with the ignition on it will NOT click, unless you do it while the fuel pump is still priming as it shares the same feed from the fuel pump relay.

They are extremely simple, it's just a solenoid which allows the ECU to have some control over the boost, it does so by PWM when powered it opens the R port and so air is allowed to 'bleed' to atmosphere so you can run higher boost. When fully disconnected (such as boost limit being reached or high ACT'S to name a couple) the valve closes the R port so boost is sent to the actuator which opens due to the boost pressure overcoming the actuator and hence actuating the wastegate so you run less boost.

I would check the actuator condition.

Martin