Motion clip black video with sound , work around

I found that when I see black video but I have sound , I can tap on the face recognition little circle, then go back and tap the play button , and video plays normally, no need to download it.
Eufy, many people having this problem , you need to fix this issue

I have the same problem since yesterday. But this workaround doesn’t work on my iPhone. Reinstalled the App didn’t work, too. Only downloading will help to the the real video and not a black screen with sound. Any other ideas?