soundbar keeps randomly switching to tv input by itself when i'm using bluetooth.

Diagnosis

This behavior is caused by a conflict between the HDMI-CEC (Consumer Electronics Control) protocol and the soundbar's internal input priority logic. When the Polk MagniFi Mini AX is connected via HDMI ARC/eARC, the TV periodically sends "keep-alive" or "active source" signals through the HDMI cable. If the TV detects a change in state—such as a background app updating or a sleep timer ticking—it sends a command to the soundbar to switch back to the primary HDMI input, effectively "hijacking" the session from your Bluetooth device.

This is particularly common with Samsung (Anynet+) and LG (SimpLink) televisions. The soundbar interprets these HDMI handshakes as a request to return to the TV audio stream, overriding the Bluetooth connection. You can confirm this is the issue if the soundbar switches inputs immediately after the TV wakes from a standby state or when you launch a specific app on the TV while your phone is still connected via Bluetooth.

How to Fix It

To stop the TV from overriding your Bluetooth connection, you must disable the HDMI-CEC handshake capabilities on the soundbar. Follow these exact steps:

1. Power on the MagniFi Mini AX and ensure it is currently in Bluetooth mode.
2. Press the Settings button on the Polk remote control to bring up the on-screen menu (if using a compatible display) or the LED indicator status.
3. Navigate through the menu options using the arrow keys until you highlight HDMI CEC.
4. Press the center select button and toggle the setting from ON to OFF.
5. Once disabled, power cycle the soundbar by unplugging the power cord from the wall for 30 seconds.
6. Plug the unit back in and reconnect your Bluetooth device; the soundbar will no longer listen for the "switch to TV" command from the HDMI cable.

If That Didn't Work

• Disable CEC on the Television: If the soundbar setting doesn't hold, you must disable the feature at the source. On Samsung TVs, go to Settings > General > External Device Manager and toggle off Anynet+. On LG TVs, go to Settings > All Settings > General > Devices > HDMI Settings and disable SimpLink. This prevents the TV from sending the signal entirely.
• Update Firmware via Polk Home App: Outdated firmware on the MagniFi Mini AX can cause "input hopping." Download the Polk Home app on your smartphone, pair the soundbar, and check for a firmware update. Specifically, look for updates that mention "HDMI stability" or "Bluetooth connectivity improvements."
• Isolate the HDMI Cable: A damaged or low-quality HDMI cable can cause intermittent electrical shorts that the soundbar misinterprets as a CEC command. Replace your current cable with a certified High-Speed HDMI cable with Ethernet (HDMI 2.0 or 2.1) to ensure the handshake signal is clean and not triggering false input switches.
• Clear Bluetooth Cache: Remove the soundbar from your phone's "Saved Devices" list and perform a factory reset on the soundbar. To reset, hold the Volume Up and Volume Down buttons simultaneously for 5 seconds until the LED flashes. Re-pair the device to clear any corrupted pairing data that might be causing the connection to drop and revert to HDMI.

Heads Up

• Disabling HDMI-CEC means you will no longer be able to use your TV remote to control the soundbar's volume; you will need to use the Polk remote or the physical buttons on the device.
• Avoid placing the soundbar directly on top of a high-heat emitting receiver or amplifier, as thermal throttling in the AX series can occasionally cause the logic board to reset and default to the HDMI input.
• If you frequently switch between TV and Bluetooth, consider using a dedicated Bluetooth transmitter plugged into the TV's optical out instead of the soundbar's internal Bluetooth to bypass CEC entirely.
• Ensure the soundbar is plugged directly into a wall outlet rather than a crowded power strip to prevent voltage drops that can trigger spontaneous rebooting or input switching.