Use esp32 ble, some modules connected ble4.0 slave device is unstable.

[z43740979]

I used the esp32 ble, with esp32 as the bb host device, found that some modules can quickly search for ble4.1 devices and can connect to the data communication, but not search ble 4.0 device, so Not connected. I can make sure ble4.0 the device is normal. Some modules as a host device, you can search ble4.1 and ble4.0 devices, and can be connected, but with the ble4.0 equipment connected to instability, and ble4.1 equipment and data communication are very stable.