Hi, I noticed when running the ButtonLED sketch that the local name is set to "ButtonLED" in the sketch, but appears as "ButtonLE" on the central device. At first I thought it was Windows truncating the name to 8 bytes, but turns out the truncation occurs on the Arduino.
The local name is part of the BLE advertisement packet that also includes the service GUID and other details. The packet is limited to 31 bytes as defined in ble_protocol.h. BLEPeripher.cpp will truncate the local name if needed giving priority to the GUID. In this case, the ButtonLED sketch uses a 128-bit GUID and that limits the local name to 8 bytes.
I recommend updating the sketch with a local name of "BtnLED" or similar.