Thank you for your efforts.
You provide an example for a HELTEC LoRa32 v2 device using LMIC library.
In the meantime a v3 device is out with other CPU (ESP32-S3) and other LoRa chip (SX1262) . The LMIC-lib is outdated and does (currently) not work with this device.
The Heltec WiFi Kit Series (V0.0.7) [https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series/releases/tag/0.0.7] (Basetype: LoRaMac-node) is (currently) the only working environment.
PLS provide an updated example for the new version of the HELTEC LoRa32 board.