Voice Isolation Unavailable Using External Microphone with FaceTime MacOS 15.1.

I know this has been asked before but I cannot comment anymore, so I start a new thread.

Although Voice Isolation is selected for the external microphone in the FaceTime MacOS app (MacOS 15.1. currently), after connecting a FaceTime Video or Audio call, Voice Isolation is auto changed to Standard. Voice Isolation is then grayed out and cannot be selected until the FT call ends. Caller's on the other side of the call hear their voices echo back to them, as the echo cancellation feature of Voice Isolation is not working.

I am using external speakers for audio. Echo cancellation using Zoom, Microsoft Teams, and other video conferencing MacOS apps work without issue, meaning callers on the other side of the call do not have the echo issues they have with FaceTime using the identical system settings and microphone/speaker set up. Its an issue unique to FaceTime on MacOS for some reason, even though MacOS natively supports echo cancellation.

Is someone working on a fix for this years long issue? When do you expect resolution?

Screen captures of my FT app and MacOS settings prior to initiating a FT video or audio call are here to assist you:

This is what it looks like during a call.

I guess something has changed as I am currently using my speakers directly connected via usb to my macbook and an external vocaster one for my mic input.

Before I used a Scarlett 2i2 and I think it worked nicely, but I needeed a mono input soundcard as apple voicerecordings can only record mono with a mono soundcard, so I switched to the vocaster