Hi,
Sorry for the delay. I have performing different tests to narrow down the problem. I found that the errors are related to the number of coeff taps are not sufficient to achieve your interpolation. I have tested increasing the coeff no. in the "Coefficients" tab of the IP Editor to a dummy amount of 147 and the errors go away. Sorry as I am not a FIR specialist and could not really comment the right coeff no. to use for your specific case. You might need to further explore into this.
Please let me know if there is any concern. Thank you.
Best regards,
Chee Pin