Question Second SSD does not 'wake up' after Sleep mode

[Ontis]

Greetings.
I have a Lenovo ThinkBook 15 G2 ARE notebook PC that originally had one 'stock' SSD 256GB device. Afterwards I needed to install an additional SSD 1 TB device in a second M2 PCIe slot.
After installing that additional SSD the system worked absolutely fine, there was no issue except one: whenever I tried to put the laptop in 'sleep mode', the second SSD never 'woke up'. The system did wake up properly, but I couldn't access any files on the second SSD. Furthermore, after multiple attempts to open anything from the second SSD the PC simply switched off the screen (but not the power) and I had to manually power it down > turn it back on to restart the system. Hibernation file was kept on the first SSD.
Turning PC off did not cause any issues, the second SSD always worked fine after shutdowns/reboots. It only 'glitched off' whenever I used Sleep mode.

The second SSD model is CRUCIAL P5 Plus 1TB M.2 NVMe. It is a PCIe 4.0 drive, but all guides declare it 'backwards compatible' with PCIe 3.0 interface.
I tried to contact the service center 'authorized by Lenovo' in my country/city, but they were unable to resolve the problem.

Did anyone else experience something similar to the symptom of 'SSD not waking up from sleep mode'?

 

[Ralston18]

Does the second SSD appear in Disk Management?

Open the window, expand so everything can be seen. Take a screenshot and post the screenshot here using imgur (www.imgur.com)

 

[Ontis]

Does the second SSD appear in Disk Management?

Open the window, expand so everything can be seen. Take a screenshot and post the screenshot here using imgur (www.imgur.com)

Unfortunately, I've already brought the laptop back to the service center so that they could dismount the second SSD while keeping the warranty.
But back in the days when I kept trying to solve this issue by myself, I checked the 'Device manager' after waking up the PC from the Sleep mode. The second SSD WAS in the list of devices installed, with 'device working properly' status in the window. But the file manager refused to open this disk and eventually the PC crashed again and had to be rebooted manually.