I suspect that the "miri=0" device detected on your screenshot comes
from the old opensource driver.
When you build gr-osmosdr, at the end of the "cmake ..." it prints a
summary of which backends it has enabled. Clearly, sdrplay should be
in the enabled section.
Be careful not to mix source and binary installations of gnuradio,
gr-osmosdr and gqrx. If you decide to pursue the build from source
method, everything has to be built from source and binary packages
uninstalled. Otherwise you don't know what is used when.
Alex