Please look at the TaxTim questions and your answers. You will need to have selected to complete the IRP5/IT3a Income section, and you will need to have entered that amount next to source code 4018 at the question that asks
"On your IRP5 under "Deductions/Contributions", do you have any amounts there? Ignore the amount next to 4497."
If you enter the amount there, then the popup warning you mention won't appear and you can continue to submit.
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