If your load is purely resistive, the pf should be 1.00. So There is a problem. My first suspicion is a bad CT or a that the CT is not securely closed. If you have another CT, try configuring that, clamping it to the same wire as the other, and comparing the readings.
If they read the same, then I’d like to see a screenshot of the inputs configuration for the CT, and a closeup picture of the CT that shows the model number.
Also, a description and picture of the load. Upon closer examination of the picture that you posted, it’s likely that your load is not purely resistive. Your multimeter is reading .308 Amps yet the IoTaWatt is saying .58 Amps. The power of 97 Watts at 240 Volts is consistent with a reactive load with a power factor of .65. I don’t see how that could be the case if the load is purely resistive. Do you have a 100W lightbulb to test with?