No sound when cast Google Photos to Chromecast using iPhone?

Question

Problem: when I cast a video from Google Photos to Chromecast using my iPhone, I see that only the image of the video is cast to TV, the TV has no sound and the frame is lag, the sound remain on my iPhone, but if I press home on my iPhone, then the casting to my TV stopped.

Then I try using Google Photos on my friend's Samsung Android to cast a video, and it works perfectly.

I see that this problem exists since 2018, many has complained:

• No sound when I cast videos from the Google Photos app to my TV, audio only plays from my phone.

• No sound when casting Google photos to tv. All other apps like Spotify and youtube works fine .

• iOS Photos App, Cloud-Only Video to Chromecast (2&3): No Sound from TV, only iOS device

This is the end of 2020 and it's still not fixed. So I don't expect Google will fix this on iPhone.

Some user said

When a local copy exists on iOS device, the picture quality on the TV is noticeably better than that of cloud-only videos. This suggests to me that the app is streaming the local version of the video, when available, directly from the iOS device to the Chromecast. When a local copy is not available, it's clearly using a different process to cast the cloud-only video, and that's where the issue is. While this may make perfect sense on an Android, Photos app for iOS is billed as a cloud service.

So beside having a local copy exists on iOS device, is there other way? Or I guess I'll just buy a Samsung Android to cast Google Photos video.