Unable to connect or upload to the PLC

I am unable to connect or upload to the PLC through the TIA portal V16.

Although I can see the PLC on the network when I search for it through the start search I cant go online and I get the message “Connection Failed - The Selected Online target could not be reached (0130: 000002).

My standard setup is to connect to the PLC and a HMI through an unmanaged (dumb) ethernet switch. I have tried connecting the programming PC directly to the PLC but with the same outcome. I am confident the ethernet switch is OK as the KP300 HMI is able to connect with no problems.

The PLC is showing up in the online access section but when I go into the online & diagnostics the menu seems to take an unusually long time to load and there is no info in the general section (e.g. firmware version, hardware info etc). I have tried assigning a new IP address in this menu too but with no success, I get the message “The set command could not be executed”

The error light on the PLC is off and I have never seen it flashing.

I have tried different RJ45 leads, checked all the voltages at the PLC and Ethernet switch and its all OK.

Hardware Details:

PLC: CPU 1212C - 6ES7212-1BE40-0XB0 

Unmanaged Ethernet switch: Weildmuller IE-SW-BL05-5TX

Programming PC : Windows 10 Pro 64-bit Version 1909, Tia Portal v16 update 2