RTL-SDR v3 dongle only works with SoapySDR source.

[blacksmock]

I am using Lubuntu 20.04.3 LTS and I have found SDR++ 1.0.3 and 1.0.4 work very well with my Airspy HF+ and Airspy Mini SDRs, but in order to use my RTL-SDR dongle, I have to use the SoapySDR source. I have blacklisted the DVB-T modules in etc/modprobe.d/blacklist-rtl.conf. The RTL-SDR dongle functions OK with GQRX, welle.io and Qt-DAB programs. SDR++ crashes when using the RTL_SDR source when I try to start DSP and I receive the following error message:
symbol lookup error: /usr/lib/sdrpp/plugins/rtl_sdr_source.so: undefined symbol: rtlsdr_set_tuner_bandwidth.
From what I can see on the net this seems also to be a problem with librtlsdr. It's not a great problem for me as I can always use one of the Airspys. I borrowed another RTL-SDR dongle and it behaves in the same way.