iOS: "No Phone Connection" message displayed on watch despite being paired and connected via Bluetooth

Just got a Venu 2 Plus and paired the watch to my iPhone 13 mini. Siri works for about an hour. Then when I press the shortcut button on the watch it says No Phone Connection. Watch syncs to Connect app just fine and getting phone notifications. I’ve already reset the watch and repaired it. Works again for about and hour then I get the same No Phone Message. Any ideas?