IOS BLE Print (Printer disconnects)

I am using BLE print to connect and print with a zebra printer (zpl)

my work flow is as follows
Step 1. Scan printer,
Step 2. Connect to the selected printer,

Step 3. discoverServices

Step 4. discoverCharacteristics,

Step 5.  peripheral writeValue for Characteristic discovered

Step 6 wait to complete and disconnect

And this seems work fine, but in some devices after lots of successful prints just randomly loses connection, (ie the printer is not connecting to the iOS )

is there any solution for this ?