Initialization of N300 fails at times

Sometimes, the initialization of the N300 fails with the error message

[INFO] [UHD] linux; GNU C++ version 7.3.1 20180303 (Red Hat 7.3.1-5); Boost_106900; UHD_3.15.0.0-70-g42b6fcf6
[PHY]  2021-12-08 09:14:03:504  init feptx thread 1
[PHY]  2021-12-08 09:14:03:535  init feptx thread 2
[PHY]  2021-12-08 09:14:03:559  init feptx thread 3
wait RUs
[PHY]  2021-12-08 09:14:03:559  Waiting for RUs to be configured ... RC.ru_mask:01
[HW]  2021-12-08 09:14:04:003  Found USRP n3xx
Found USRP n300
[INFO] [MPMD] Initializing 1 device(s) in parallel with args: mgmt_addr=192.168.18.240,type=n3xx,product=n310,serial=31641BC,claimed=True,addr=192.168.10.2,second_addr=192.168.20.2,clock_source=internal,time_source=internal,master_clock_rate=122880000.000000
[ERROR] [RPC] Someone tried to claim this device again (From: 192.168.18.194)
terminate called after throwing an instance of 'uhd::runtime_error'
  what():  RuntimeError: Error during RPC call to `claim'. Error message: Someone tried to claim this device again (From: 192.168.18.194)
Linux signal Aborted...
/home/oaicicd/robert/openairinterface5g/executables/softmodem-common.c:198 signal_handler() Exiting OAI softmodem: softmodem starting exit procedure

This supposedly results from the nr-softmodem to not properly shut down the N300. OTOH, I have never seen this from the nrUE with N300, although it uses the same driver.

Steps to reproduce:

• kill the nr-softmodem
• immediately restart the nr-softmodem (possibly multiple times, this does not seem to be deterministic)