Drive file system and fiber connected drives

[DVespoint]

I've been scouring the Avid/PT site for information on external drive and fiber connected drives for information. Any tips/help would be appreciated.

Here's the deal:
I'm running Pro Tools 11.2.1 on a beefy Mac Pro doing audio post for video.
I record to the local drive.
I am connected via fiber to a large server where I place files for my video editors. On this same server we have placed our SFX library and our production music library so the video editors can audition and choose music/sfx.
That server was once an Apple XSAN, now it is a Promise raid...
I can no longer drag files from the server into projects or use the Workspace to audition SFX or music files (NOTE: I can search, but need to use the "locate with Finder" to get the files and move them to my machine. I could before -- and I am not sure if it is a drive issue or a PT version issue.

Why is this? Is it the file system on the server? The Mac sees the server as a local drive. ...and if so, what are the specs for the file systems for Pro Tools - cant find that anywhere. Our video editors use the server effectively with their Adobe products, its like having a 120TB local drive ...

Any answers, tips, links are welcome...
thanks all,
DV