1, no power
Bluetooth headphones are battery powered. If the battery is out of power or damaged, it will often disconnect automatically.
2, the interference source is too strong
Bluetooth headset is working at 2.4g frequency, this frequency also has wifi router, cordless phone and 2.4g mouse. These are relatively strong sources of interference. 3, the quality of the earphones is not good
Especially the refurbished earphones, just bought normal, with a period of time there is a problem.
Some Bluetooth headsets, used in other brands of mobile phones, sometimes automatically disconnected. It's a compatibility issue.