LoRaWAN stopped working for my application, to verify my Application isn't wrong i tested the lorawan-example and found it also not working.

Description

lorawan-example does not work any more (branch: master) it stops after trying to send the message.

last working commit:6dfc07b0761abe685b6a935cc0b4a1fc87178394
just before "adapt to v4.4.1"

my REGION is set to EU868.

Steps to reproduce the issue

enable debugging in semtech-loramac.c
build and flash the loramac-example
'''
#make clean flash term

xx:30:07,821 - INFO # [semtech-loramac] MAC timer timeout
xx:30:08,063 - INFO # [semtech-loramac] MAC timer timeout
xx:30:08,156 - INFO # [semtech-loramac] MLME confirm event
xx:30:08,160 - INFO # [semtech-loramac] join succeeded
xx:30:08,164 - INFO # [semtech-loramac] loramac join notification msg
xx:30:08,166 - INFO # Join procedure succeeded
xx:30:08,168 - INFO # Sending: This is RIOT!
xx:30:08,172 - INFO # [semtech-loramac] loramac cmd msg
xx:30:08,177 - INFO # [semtech-loramac] send frame This is RIOT!
xx:30:08,186 - INFO # [semtech-loramac] MCPS request: confirmed TX
xx:30:08,191 - INFO # [semtech-loramac] MCPS request: dutycycle restricted
xx:30:08,201 - INFO # [semtech-loramac] loramac TX status msg
''''

Expected results

working example
'''
xx:45:23,723 - INFO # [semtech-loramac] MAC timer timeout
xx:45:24,612 - INFO # [semtech-loramac] MAC timer timeout
xx:45:25,568 - INFO # [semtech-loramac] MAC timer timeout
xx:45:26,524 - INFO # [semtech-loramac] MAC timer timeout
xx:45:27,480 - INFO # [semtech-loramac] MAC timer timeout
xx:45:27,721 - INFO # [semtech-loramac] MAC timer timeout
xx:45:27,820 - INFO # [semtech-loramac] MLME confirm event
xx:45:27,823 - INFO # [semtech-loramac] join succeeded
xx:45:27,827 - INFO # [semtech-loramac] loramac join notification
xx:45:27,829 - INFO # Join procedure succeeded
xx:45:27,832 - INFO # Sending: This is RIOT!
xx:45:27,834 - INFO # [semtech-loramac] loramac cmd
xx:45:27,838 - INFO # [semtech-loramac] send frame This is RIOT!
xx:45:27,841 - INFO # [semtech-loramac] MCPS_CONFIRMED
xx:45:27,850 - INFO # [semtech-loramac] MCPS request OK
xx:45:28,802 - INFO # [semtech-loramac] MAC timer timeout
xx:45:29,758 - INFO # [semtech-loramac] MAC timer timeout
xx:45:30,713 - INFO # [semtech-loramac] MAC timer timeout
xx:45:30,858 - INFO # [semtech-loramac] TX timer timeout
xx:45:31,670 - INFO # [semtech-loramac] MAC timer timeout
xx:45:31,673 - INFO # [semtech-loramac] MCPS confirm event
xx:45:31,674 - INFO # [semtech-loramac] loramac TX failed
xx:45:31,678 - INFO # [semtech-loramac] MAC reply received: 5
'''

Actual results

see above

Versions

Operating System Environment

   Operating System: "Debian GNU/Linux" 
             Kernel: Linux 4.18.0-2-amd64 x86_64 unknown

Installed compiler toolchains

         native gcc: gcc (Debian 8.2.0-9) 8.2.0
  arm-none-eabi-gcc: arm-none-eabi-gcc (15:7-2018-q2-4) 7.3.1 20180622 (release) [ARM/embedded-7-branch revision 261907]
            avr-gcc: avr-gcc (GCC) 5.4.0
   mips-mti-elf-gcc: missing
         msp430-gcc: missing

riscv-none-embed-gcc: missing
clang: clang version 6.0.1-9.2 (tags/RELEASE_601/final)

Installed compiler libs

arm-none-eabi-newlib: "3.0.0"
mips-mti-elf-newlib: missing
riscv-none-embed-newlib: missing
avr-libc: "2.0.0" ("20150208")

Installed development tools

              cmake: cmake version 3.12.3
           cppcheck: Cppcheck 1.84
            doxygen: 1.8.13
             flake8: missing
                git: git version 2.19.1
            openocd: Open On-Chip Debugger 0.10.0
             python: Python 2.7.15+
            python2: Python 2.7.15+
            python3: Python 3.6.7
         coccinelle: missing