Thats certainly not the firmware version you want. It should be 4.19.4.48.
If you are hearing “ready to connect” you aren’t doing something right. Follow the instruction more explicitly for flashing the firmware.
When placing the file on the MicroSD, I would make sure it is the only file on there and has a full name “demo.bin”. I don’t know if it really matters, but for instance, a Mac will automatically put other files on the SDcard. I used Windows to remove all files except the .bin file.