https://devzone.nordicsemi.com/f/nordic-q-a/108552/bt_hci_cmd_send_sync-failure-when-changing-txpower-error--5This is similar to issues others have experienced in the past, yet the solutions from those threads aren&#39;t working for me. As per guidance from other threads, I have both of these enabled: CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL=y CONFIG_BT_HCI_VS_EXTen-USTelligent Community 13Thu, 22 Feb 2024 14:02:18 GMThttps://devzone.nordicsemi.com/thread/470285?ContentTypeID=1Thu, 22 Feb 2024 14:02:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:95cf3e62-fa8f-4806-af2f-0791230dadedcal.rubbo<p>Turns out the example code I was using was from an old project, and I wasn&#39;t passing the handle type and handle correctly!</p> <p>Copying the set_tx_power() function from this example project worked!</p> <p><a href="https://github.com/nrfconnect/sdk-zephyr/blob/main/samples/bluetooth/hci_pwr_ctrl/src/main.c">github.com/.../main.c</a></p><div style="clear:both;"></div>