Why my Phone can't auto connect to the ESP-32 A2dp sink speaker? [BT-758]

[24370239@qq.com]

1. I used IDF3.3's A2DP_SINK example as a sin speaker.
2. then my phone connect and it and can work very well.
3. then I reset my ESP32 A2DP SINK speaker, but my phone can discovery this esp_speaker, but it can't auto connect it. Why?
4. If I disable/enable my phone's BT button, my phone can auto my ESP32 A2DP Sink Speaker.

Because I used its' esp32's example and do not change anything.
Did I lost some setting for it??

[ESP_Alvin]

Moderator's note: edit the topic title for tracking, thanks.

[KBFEDE]

It's a common strategy of connection between a BT speak and phone. Mode `Discoverable and Connectable` does not mean that the phone should tempt to reconnect the speaker all the time.