this are my temporary solutionat the moment for make ver 1.4.x debug work, i siwtch debug configguration to remote gdbserver option modify config.txt in the folder "C:\ST\STM32CubeIDE_1.4.0\STM32CubeIDE\plugins\com.st.stm32cube.ide.mcu.externaltools....
i have the same problem too, 1.4.x work perfectly on my new HP laptop, but not working on my old DELL laptop. no st-link detected when star debug. is the problem solved ?