https://devzone.nordicsemi.com/f/nordic-q-a/54035/immediately-disconnected-reason-0x3eHey guys, I&#39;ve been troubled by the this 0x3E issue for almost disappointed to Nordic. I&#39;m working on a CENTRAL,which is going to connect a headphone with to read some information.It is an easy application. I started from the example ble_app_hrs_cen-USTelligent Community 13Thu, 14 Nov 2019 09:36:17 GMThttps://devzone.nordicsemi.com/thread/220030?ContentTypeID=1Thu, 14 Nov 2019 09:36:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5d9fb016-ed86-4d42-a823-141216bff9e1Mttrinh<p>Hi,</p> <p>Can you provide me with which chipset that is used in the peripheral? and which brand and model of the headset?</p> <p>Which Nordic-kit are you using? Do you have other nordic-kits you can test with?</p> <p>Can you also provide me with which SDK and Softdevice version you are using?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/219351?ContentTypeID=1Sat, 09 Nov 2019 06:40:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1f1fccc5-2887-4d73-9d1e-5518178e06ebdaoms<p>Yes,it happens almost every time.Very ocasionally,it is able to make the connetion.</p> <p><span>Use nRF Connect on the phone is always OK.</span></p> <p>I sniffer the packets and found that after CONNECT_REQ,the central indeed sent other 6 EMPTY PDUs to the headphone,but the&nbsp;headphone doesn&#39;t respond.</p> <p>From the sniff track,I found that the only difference is WINDOW SIZE and WINDOWS OFFSET,on my central window offset is 0ms ,while the phone APP has 2.5ms windows offser. Does this matter?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/219107?ContentTypeID=1Thu, 07 Nov 2019 14:51:24 GMT137ad170-7792-4731-bb38-c0d22fbe4515:210096a4-bf93-4365-b0f7-cbc2eb2a8f38Mttrinh<p>Hi,</p> <p>BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED means connection failed to be established. Does this error appear everytime?</p> <p>When you say phone app, you mean nRF Connect on the phone?</p><div style="clear:both;"></div>