hard drive in caddy gone after pm-suspend

Hi all, I bought a SSD to upgrade my laptop. And removed the HDD and putting it in a caddy to replace the DVD. I would like to use this configuration to backup my system to the HDD. I have a laptop called Lenovo T540p. The issue is here: de HDD disappears after a pm-suspend. It s totally gone and spinning. What is the best way to investigate? Any tips are welcome! Regards, Marco P.S. some info - Using CRUX 3.4, fully updated. - on boot the HDD (sdb) is detected.