QFlash problems with BC660K-GL

Hi,
We have a lot of problems with flashing the BC660K-GL.
We have one PC where it works fine and we can manage to load working programs in about a minute.
We want to setup up a working environment on more computers.
On a different computer we managed to get the .bin files loaded in the QFlash but we get “FAIL, DL_Probe Time out!” every time we try to flash.
We tried a 3rd computer and it flashes in about 4 minutes but the program doesn’t run after we press RESET.
We are pretty sure it’s not about the buttons or the code because it already works fine on the first computer.

What can cause these behaviours?

BC660K firmware upgrade, you need to first pull down the BOOT pin do not relax, enter the download mode, then click Qflash’s “start”, then reset the module, at this time if has entered the download state, release the BOOT pin