"Up One Level" button not working on network directories

[Kmjec]

I use XnView Classic, v. 2.51.6, and Libformat 7.172 on Dell computer T3500 with W10.
I have a problem using the "Up One Level" button in the browser if I am in the network directory (NAS).
For instance I am at dir \\NSA320S\Eagle\2024\019-2024-T-ClassicOil-usazenina_trubka\XRF\

fig1.png

and I use "One up level" button, sw does not open one level upper dir, but my home dir at C: drive (C:\Users\Kmječovi\)

fig2.png

Similarly, when I click on subdirectory XRF in the dir mentioned above, sw opens C:\Users\Kmječovi\.
This behavior does not appear on my computer's local drives C: and D:.
Could you send any advice or help, because it is not so user-friendly?
Thank you in advance
Tomas