Make sure you are on good WiFi, keep watch awake, keep watch beside phone, and follow these steps:
OK, after trying many different suggestions, here’s what worked for me:
Unpairing and pairing did NOT work. Simply waiting 15 minutes did NOT work.
NOTE: I was connected to WiFi for all of the above AND below attempts.
1. I turned off the Auto Lock in settings so the phone would stay awake.
2. I opened “My Watch” on the phone, and deleted the Mickey watch face. (I had added only the Mickey)
3. I added BOTH Mickey AND Minnie faces to “My Watch” and left the phone on the “My Watch” screen for about 20 minutes.
Both Mickey and Minnie now speak the time audibly.
IF ONLY ONE speaks after doing this, simply toggle the “tap to speak time” switch off and back on for the one not speaking, and leave side by side for 15 more minutes with above restrictions.