Hi Paul,
I've experienced a similar problem with my Synology, but only with the "home" shared folder that actually redirects to /volume1/homes/username. If I mount homes/username directly, then I can open spotlight results correctly. I spoke with Synology support and they indicated this is a known issue with macOS but they have no intention of fixing it. The confusing part is that Synology support indicated that the problem is with network locations called "home" rather than with any other details of how they implemented the "home" network volume.
This problem is not only when operating on spotlight results in the "home" folder, but anytime Finder tries to alias anything in "home", e.g. when working with file/folder aliases in AppleScript.
Unfortunately, Synology sounds uninterested in a fix for this problem.
Here's my conversation with Synology support:
Them:
...
This is likely related to other known issues with the home directory in regards to the macOS. Because of the way that the macOS treats the home directory there are some network features that simply won't work.
For example Microsoft Office for Mac can't access files in the "home" shared folder.
Unfortunately, the only work around in cases like this is to simply not use the "home" shared folder.
Me:
... The KB article you linked to says '...Microsoft Office 2011 for Mac has problems accessing files stored in any network shared folder named “home”’. Regarding the “…any network shared folder named “home…” part, is it really the name of the network volume that is causing the problem? If that’s the case, then a custom name for each user’s “home” would suffice as a workaround, right?
Has Synology looked deeper into this issue?
...
Them:
In cases like this, yes the issues is simply the name of the network volume. You can create your own Custom Shared folders and name that whatever you'd like, and they should work. However, there is no way to change the name of the default home/homes shared folders.