I have both the RF7020 V4.0, (actually a Dorji DRF7020-D13 V4.0), and APC220 V3.0 modules, and both types work fine, using the same config utility and provided USB-TTL converter.
I note that you said your earlier ones were RF7021, not RF7020. Unless this is a typo, they would have been based on a different chip, I guess. The APC220 modules are based on the ADF7020 chip, and the RF7021, (A Dorji DRF7021), would have been built using the ADF7021 chip.
I'm not sure if that's the reason for the problem. You might possibly have previously used a different config utility for the 7021.
You do have the CP2102 driver installed, I assume?
So, for your new modules, you could try downloading the config utility specifically intended for the APC220/DRF7020, and see if that solves your problem.
Here's a download link for the APC220 utility.:-
RF Magic Configure Software