no problem, you’re welcome. but you have to mention also when the problem is fixed 
about the printf: my intention was to use an additional printf to the console, so that you can see if some requests are ariving. Using one printf shouldn’t change anything, right.
Oh, and one more pitty pitfall when the host is running Windows 10:
Windows 10 is doing some mysterious on the USB MSD that the Nucleo provides. This leads to resets of the board, I had this problem many times with different boards.
A workaround is to disable the USB MSD in the device properties.
To verify, you can print a startup message to the terminal or blink a LED until a button is pressed to continue.