Funny people disagree on this.
The Google app was updated on 16 January 2020. Now, it seems, as long as I have access to 'Hey Google' turned off in the settings of the assistant app, I can have permissions set to 'Allow' for the microphone for the Google system app and get stereo recording. This never used to be the case and it had to be set to 'Deny' regardless of whether 'Hey Google' was turned on or off.
By using the n-track app I can get stereo recording too, if the driver is set to OpenSLES and the source set to 'No processing' but as with the modded Recorder app and the inbuilt camera app, I only get stereo if 'Hey Google' is turned off. Using the Hi-Q app I can't get stereo at all no matter what setting I try.
I live in Brazil, and I realized this same problem that you face. Thanks to your tip, disable Hey Goolge.
I hope Nokia will require an update by updating this price.
I'm getting the same issue with my new Nokia 5.3. When "Hey Google" hotword is enabled, videos are recorded with mono audio. If I turn off "Hey Google", videos are recorded with stereo audio.
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