MBED1768 programming issue

Hello All,
I have 3 Mbed1768 units with programming issues

1st one is old (dark colour) ,works fine with MBED studio.When I press RUN it erase the chip and when I press reset it runs the program and works fine. It used to run the program without hit reset after download the new program into chip. I dont know why its not doing that anymore.

2nd one bought brand new from Cool components. Its blue color .
When I press RUN the compiler says erase the chip and its running but it doesn’t. When I copy the BIN file into it its works but slow. I mean I tested with blnky 500ms , the led stays on like 5S

And once I compile and run the programs , the RUN, Build button grayed out. To activate those I have to unplug and replug the USB. Any Ideas??

I almost finish a project with my OLD one I wanna make a copy.