External Microphone Not Working with macOS 26.01 Phone App

Is anyone else experiencing this issue? My external microphone functions perfectly in all other applications, and I can see the input level bar moving as expected. However, when I place a call using the new Phone application on macOS 26.01, the app seems to disable the microphone entirely. Once the call ends, the mic resumes normal operation.

I attempted to grant the Phone app microphone access through System Settings → Privacy & Security → Accessibility, but the app doesn’t appear in the list, and there doesn’t seem to be a way to manually add it.

Is there a simple fix for this, or does the current version of the Phone app not support external microphones like Logic Pro and other audio-enabled applications do?

Any guidance or insight would be greatly appreciated. Thank you in advance for your help.