GATT timeout executing long write with nRF Connect

I successfully built the example peripheral project "experimental_ble_app_queued_writes" from nRF5_SDK_12.0.0_12 and successfully downloaded the app to a nRF52832 development board with subsequent automatic activation of fast advertising. I can successfully connect to the resulting "Queued_Write" peripheral with the nRF Connect software that interfaces with a nRF51 dongle. I can successfully access the "UART over BLE" service with the associated single characteristic that is supposed to support long writes. However, when I actually try to write some number of bytes to this characteristic, nRF Connect eventually times out with a "Received a Gatt timeout" message. My assumption would be that this should work correctly with no user modifications since it is Nordic example code running on Nordic hardware and interfacing with the nRF Connect software also running on Nordic hardware. What's going wrong? Thanks for the help.