Different Outcome when using PSexec with cmd and cmd locally

Question

Hi, i´m experiencing this strange behaviour:

when im logged on as User xyz on computer 123 (locally in a command shell) and do dir \server\sharename -> the files are beeing displayed

doing the exactly same after connecting to the computer via "psexec \123 cmd" from a remote machine -> the result is "Access denied"

BUT: after double and thrice-checking:

WHOAMI -> same domain\user
IPconfig -> same information > so definitely on the same machine

firewall also gets the same packets towards the target when using either method.

So : any clue why starting a cmd via psexec on a remote machine should lead to a different result than using cmd locally ?

I have never had problems with pstools like that and am quite confused at the moment.

Any help is really appreciated !

Kind regards !