None of those articles are any help, I hear my Garmin fine via the Garmin speaker, it's just Alexa. Alexa is ignoring the setting.

I am using the USB cable that came with the Garmin. It powers up the Garmin (even when the battery is stone dead). But it refuses to charge it. I tried another USB power brick I have that delivers 3 amps and same issue. Plug it into the car adapter from the car and it charges.