Q: Answering a phone call on Apple watch with MFI hearing aids

I would like to ask anyone who uses an Apple watch with MFI hearing aids what happens when they answer a phone call on the watch.

Does the audio go straight to your hearing aids?...or are only the watch mic and speaker active?

I have just seen someone say that it goes straight to HAs but mine only works on the watch if I answer on the watch.

If I answer on the phone it goes straight to HAs.

I wonder if I am missing a setting.

I am using ReSound Enzo 9 HAs with 9.2, but I would like to hear from users of any brand of HAs.

Thanks