No spectrum but errors

[122christo]

I am using Linux Mint 20.3 and started Qspectrumanalyzer from the console.
The SDR device is a rsp1 clone from china. If I start Qspectrumanalyzer I got no spectrum, but errors in the console:

Starting backend:
/home/christoph/.local/bin/soapy_power -f 87.0M:109.0M -B 10.0k -T 10.0 -d -r 1000000.0 -p -35 -F soapy_power_bin --output-fd 27 -w 1536000.0 -g 20.0 -k 20.0 -c --even --fft-window boxcar --remove-dc

[INFO] devIdx: 0
[INFO] SerNo: B0008P0001
[INFO] hwVer: 1
[INFO] rspDuoMode: 0
[INFO] tuner: 1
[INFO] rspDuoSampleFreq: 0.000000
Traceback (most recent call last):
File "/home/christoph/.local/bin/soapy_power", line 8, in
sys.exit(main())
File "/home/christoph/.local/lib/python3.8/site-packages/soapypower/main.py", line 317, in main
sdr = power.SoapyPower(
File "/home/christoph/.local/lib/python3.8/site-packages/soapypower/power.py", line 35, in init
self.device = simplesoapy.SoapyDevice(
File "/home/christoph/.local/lib/python3.8/site-packages/simplesoapy.py", line 109, in init
self.corr = corr
File "/home/christoph/.local/lib/python3.8/site-packages/simplesoapy.py", line 288, in corr
corr_range = self.get_frequency_range('CORR')
File "/home/christoph/.local/lib/python3.8/site-packages/simplesoapy.py", line 400, in get_frequency_range
freq = self.device.getFrequencyRange(SoapySDR.SOAPY_SDR_RX, self._channel, tunable_name)[0]
IndexError: tuple index out of range

How to fix this? What am I missing?
Thanks Chris