Qcad v27 and themes

I must be doing something wrong, I use this in the terminal to start Qcad…

/home/pete/opt/qcad-3.33.1-pro-linux-qt5.14-x86_64/qcad -config /home/pete/.config/QCAD/QCAD_3

2nd line in the terminal is…

absConfigFile: "/home/pete/.config/QCAD/QCAD_3"

and further down I get…

19:48:09: Debug: openFiles: -config,/home/pete/.config/QCAD/QCAD_3

but Qcad only reads and writes to the QCAD3.conf file ?