Hello, the designation Softbundle means that the hard drives are not physically pre-installed in the system. Hopefully this will be useful to you. Erol, Lausanne
Unfortunately, the SSD is not listed under compatible products at Synology. Unfortunately, I cannot judge whether this is the same as non-compatible.
The following product would be in the list: Samsung 960 EVO (250GB, M.2 2280)
Compatibility list: https://www.synology.com/de-de/compatibility?search_by=products&model=DS918%2B&category=hdds&filter_brand=Samsung&p=1