Welcome to the forum @katobalano
I think the main problem is that you’re no longer in your old user session, but SYSTEM (presumably you found that your own user lacked enough access).
Is this an open share (a bit dangerous, but some home users might do that)?
Typing UNC path (starts with double blackslash)? Or do you use drive letters?
Is this Source or Destination? I think SYSTEM service gets difficult either way.
is still only in Canary (testing) releases, but if normal means (e.g. on Destination, type the UNC path and maybe enter Username and Password) fail, it might help.
Surprising to me (but nice to see), it’s even documented in the user manual now.
I’m wishing the new code put the emphasis on SMB, as CIFS is kind of obsolete.