You have to download https://www.st.com/en/development-tools/stsw-link004.html#get-software
if you want to program the pill with the st-link (I recommend you this way), this software installs the driver required for the st-link in order to work properly and even allows you to debug your code.
The first time you open it with the st-link on your usb port, go to "ST-LINK->Firmware update" so you have the latest firmware version on your ST-link, then "File->Open File" and load the .bin file, once loaded go to "Target->Connect" and then to "Target->Program & Verify", and now if you see no error it should be working.
(Flashing times are way worse on the clones).
The errors I'm having are due to the 3.3 LDO and the bad quality capacitors on the LDO prefiltering and postfiltering, the problem are the rising edges mostly, it takes a while to get to the 3.34v level and I've got a lot of packet error, this is why it has this behavior on the menu, I guess.
As I can see you have to answer before 1ms so the bus doesn't reset the device, but I think it is not mandatory to answer with 2Mbps, a response at a lower rate like 1Mbps will be accepted by the bus as well isn't it?