Apple audiobooks not downloading to ultra 3

iPhone 16 plus / Watch Ultra 3 / OS 26.1 on both. Apple purchased audio books refuse to DL from phone to watch. Books ARE downloaded to phone / Bluetooth and Wi-Fi both on / watch connected to Bluetooth. I followed the process in the watch app on my phone (the steps are quite simple) / the download starts but it never finishes. I left one for six hours overnight last night and it only downloaded to the watch about 50 MB

I'll take any suggestions anyone may like to offer.

Thank you