A lot of users are having overheating issues with MSI AIO CPU Coolers.
Make sure the pump is working and rotating at its normal RPM speed.
That Fluid is flowing through the tubing, You should feel a slight vibration.
The input hose is slightly cooler than the output hose from the processor.
There is no Air obstruction to the Radiator nor Radiator's fans.
The fans are spinning at maximum RPM when the processor is getting very hot.
Another User needed to change the Pump's Motherboard connection to another port (CPU PWR 2)
Check to see if the pump is spinning at its normal RPM.
Otherwise you can temporarily install a Air CPU Cooler and see if the temperatures are cooler. If they are then you know the problem is with your MSI AIP CPU Cooler.
Open a MSI Support ticket and see what they suggest.