Thank you. This is it.
I failed to notice that there are Zigbee-specific partitionings and I simply accepted the already selected scheme that seemed to hold the called-for parameters.
My inexperience with this environment. The sketches now run correctly.
Thanks again.

In the Arduino IDE, partitioning is offered under Tools. As I posted, I selected exactly the one that the example calls for.
Is there another list? Where?
Thx.

WaveShare esp32-c6-dev-kit-n8
Arduino IDE: 2.3.6 2025-04-09
Library: https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
Board: ESP32-C6 Dev Module
Other Tool settings:
- erase all flash
- JTag: (tried all of) Disabled; Integrated USB; FTDI; ESP-USB ...