Have you already made sure that the flexible PCB is not inserted upside down? And also checked that the NVMe is properly inserted into the socket as described in this and the following article?:
PS: If the problem persists, please be more specific. You have not mentioned about:
- Current installed bootloader version, for example: 2024-09-10
- Model number of the power supply you are using
- Is the NVMe not working in both cases, or only in one of them
- Operating system/distribution
- Capacity, firmware, model number of the NVMe
- Content of bootloader config/EEPROM
- Photo of the boot screen
- …