The adjustment only increases the difference and, it also seems to reset to no adjustment when a subsequent track plays.
This is a good one! Here are Amazon’s list of steps to troubleshoot:
- Verify that your devices are compatible with home theater mode (I put a list of compatible devices below.)
- Verify that your Echo speakers are “online” in the Alexa app.
- Connect all devices to the same Wi-Fi network (make sure they’re all on the same 2.4 GHz WiFi network, not 5Ghz.)
- Turn up the volume on your speakers.
- Play a video title from a different streaming media app.
- Make sure to select the home theater audio option on your Fire TV to match your activity. For video playback disable Gaming Audio. For gaming, enable Gaming Audio.
- Restart devices in your home theater group. For Echo devices temporarily unplug them from power. For Fire TV, go to Settings > My Fire TV > Restart. Wait a few minutes before playing content.
If the issue persists, delete the home theater group in the Alexa app and set it up again.
Compatible Fire TV Devices
- Amazon Fire TV Stick 4K
- Amazon Fire TV (3rd Generation)
- Fire TV Cube (1st Generation)
- Fire TV Cube (2nd Generation)
- Amazon Fire TV Stick (3rd Generation)
- Amazon Fire TV Stick Lite
Compatible Echo Devices*
- Echo Dot (4th Generation)
- Echo Dot (3rd Generation)
- Echo Dot (4th Generation) with clock
- Echo Dot with clock
- Echo (4th Generation)
- Echo (3rd Generation)
- Echo (2nd Generation)
- Echo Plus (2nd Generation)
- Echo Plus (1st Generation)
- Echo Studio
If you’re still having trouble, I would recommend reaching out to Amazon directly.
Hope that helps!