BLE disconnects after a short period of time

[endian-albin]

I've noticed that BLE connections are terminated after a less than a minute. It's not due to the connecting device because it happens both with nRF Connect and BlueZ + gatt-cts-server.py.

The debug log displays this warning: bt_att: Ignoring unexpected request.

[endian-albin]

After searching for the warning message, I found something interesting in this Zephyr issue:
zephyrproject-rtos/zephyr#15714

This setting appears to do the trick:
CONFIG_BT_ATT_ENFORCE_FLOW=n

https://docs.zephyrproject.org/2.3.0/reference/kconfig/CONFIG_BT_ATT_ENFORCE_FLOW.html