This is very confusing and frustrating. All the tutorials instruct us to use ArduinoBLE library but that’s not compatible. The comment above that the mbed-enabled boards cannot use BLE makes no sense when the board description literally says “Seeed nRF52 mbed-enabled Boards. Boards included in this package: Seeed XIAO BLE - nRF52840, Seeed XIAO BLE Sense - nRF52840” it’s literally right in the name.
So when treating this as a non-mbed board, meaning a v1.1.0 board, ArduinoBLE is not available, the code does not compile - yet - when treating this as an mbed board, which supposedly does not support BLE, the code that references ArduinoBLE compiles fine. It’s backwards.
For the record, this all works, including the ArduinoBLE library and all the tutorials, if you set up the board as I’ve shown above, that is, as an mbed-enabled board. BLE works fine.