Please! ANY other users device that is heard by your gateway will include the details you’ve removed in their uplink meta data. And join requests are sent in plain text so will appear in any gateway logs that hear it. You’ve taken time to redact some information but then leave other info in. From experience this means there is a likely hood that there are other things being altered that need to be left alone.
The original (German) article links to version 3.2.0 of LMIC which is old but should be co-operating. At that time it reached LW v1.0.3 so that’s OK.
You could try RadioLib which has first class support for T-Beam AND has been shown to be completely compliant for all LoRa frequencies (FSK coming soon apparently) - this will sanitise / test your board & gateway combo. At RadioLib Development Organization · GitHub you can pickup the board definitions library and at a later date use the the persistence for ESP32.
After that you can patch over the GNSS elements or you can go back to LMIC.