nRF5340 Audio + peripheral_uart integration not connecting to central_uart board but connects to nRF Connect mobile app

[pal_722]

Hi,

I am working on integrating the peripheral_uart sample with nRF5340 Audio (LE Audio) on the nRF5340 Audio DK.

Setup

Peripheral Side

Merged applications:

• peripheral_uart
• nrf5340_audio

The peripheral:

• advertises successfully
• is visible in nRF Connect mobile app
• connects successfully to mobile phones
• NUS service is still enabled

Central Side

Using modified central_uart sample:

• NUS client enabled
• fixed target MAC address filtering
• auto-connect enabled
• UART forwarding enabled

The central works perfectly with:

• plain peripheral_uart

But it does NOT connect with:

• peripheral_uart + LE Audio

even though the merged peripheral is connectable from mobile.

Observation

The peripheral MAC address is constant and not changing.

So this does NOT appear to be a privacy/random address issue.

Questions

1. Does LE Audio integration modify advertising behavior such that the bt_scan address filter mechanism behaves differently?
2. Is extended advertising (CONFIG_BT_EXT_ADV) known to affect central_uart style scan filtering / auto-connect behavior?

Any guidance on best practices for coexistence of:

• LE Audio
• NUS/custom GATT services
• central_uart based connections

would be very helpful.

Thanks.