Since the original post I have reset the permissions on the Machine A drive that is having issues as lined out in the Microsoft Support page How to use Xcacls.exe to modify NTFS permissions
. This appears to have kind of fixed the issue of opening, now it is just a matter of speed. There is a latency issue of epic proportions when trying to open even the smallest file from Machine A compared to Machine A opening one on the other two machines. Machine A can instantly open a huge file and it takes up to a 3 minutes to open a small file stored on Machine A via the other two machines.
After waiting it finally appears.
We have ran a PING via CMD and the machines all have equal up/down access so it is not a network issue.
So now we can open a file on the B & C machines, but it takes forever and the A Machine opens the exact same files on B & C instantly. Where does this put me other than even more confused?