SUMMARY
When selecting an SMB share through Dolphin, correctly logged in and able to browse directories I get a permissions error popup when trying to do any file manipulation (such as copy, move, rename files). The error message is 

"Access denied. Could not write to smb://<>username>@<ip-address>/<folder>"

This error has been popping up since the last couple of updates

STEPS TO REPRODUCE
1. Navigate to a SMB share by clicking on Network - Shared Folders (SMB) and Select Device
2. Enter credentials (username and password)
3. Navigate to a Folder
4. Try any file manipulation (copy, move, rename)

OBSERVED RESULT
 - Access denied error message

EXPECTED RESULT
- To be able to do file manipulations

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Ultramarine
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.19.0
Qt Version: 6.9.2

ADDITIONAL INFORMATION
The NAS in question is a QNAP 453D and has not had any changes to it recently (i.e firmware updates).

This has only been happening for maybe a month since updating KDE. I have received this error on one laptop first with an older laptop running an older version of KDE without issue. Since updating the older one today - the permissions error has started on the older laptop as well now. 

If I connect to the same NAS via FTP (same login credentials), I also don't get permission errors and able to do file manipulations, only via SMB.

It only seems to be an issue when connecting through Dolphin network. I also have a PC with a similar version  however connects to the same NAS except via hard links in the FSTAB file instead and doesn't have these issues.

It doesn't seem to affect read operations of any apps that try and use these SMB links (starting VLC etc to play a movie)