I’m getting all alerts on my iPhone but some of my cameras (I have 4) I only get alerts on my Apple Watch on some of the cameras. All running same firmware.
Any help is appreciated. I’ve reset all devices, phones, and watches. Both watches only get alerts from some cameras and the phones get all alerts.
I have the same issue. I have one cam pan running latest firmware 4.10.6.199 and a iPhone and iwatch. Random alerts appear on watch. Maybe 5%. Seemed to start when I eventually updated the camera firmware to 4.10.6.199. Not sure how that could affect the alerts showing on the watch. Checked the app settings on phone all is good.
Would like to add that all of my cameras only show alerts on my iPhone even when my Apple Watch is connected and showing alerts for other apps.
For a short period yesterday, I got motion alerts on my Apple watch! \o/
Today, not so much. 
Last year, alerts to the watch worked fine.
Around January, it stopped working (alerts on phone only).
For a few hours yesterday, it worked again.
Today, no alerts on my watch
I performed no config changes or software updates on any device this week.
This implies to me that the error is on the cloud side. Malformed push notification?