I would presume this is backed by github somewhere? But I cant find it or a report link on readthedocs, but
https://ble-intros.readthedocs.org/en/latest/AdvSamples/HighData/ Client to Server section incorrectly text says use GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY instead of BLE_GATT_CHAR_PROPERTIES_WRITE_WITHOUT_RESPONSE which is correctly referenced in the example