Port shows in IDE but upload (Blink!) fails after 10 attempts.
Clones from other Chinese sources using CH340 (v1.4) work OK.
Any suggestions pls.
What does the small chip near the USB port look like and what does it say on it ?
Could be you need the CP2102 driver ?
USB chip =CH340G
You could try doing a Tools > Burn Bootloader to the problematic clone. If you don't own a dedicated ISP programmer then you can use one of the working clones as an "Arduino as ISP":