SUMMARY
In my system there are two users. I have NAS where are shared folders via nfs. In /etc/fstab I have commands to mount them for me and other user. In couple cases there are the same remote directories but mounted to separate subfolders in my home user directory and home directory of other user. Dolphin running in my Plasma session shows both folders or rather all what found in /etc/fstab.
One thing is that they are duplicated, and second I don't have access to these duplicated ones.

STEPS TO REPRODUCE
1. In /etc/fstab file put at least two commands for mounting the same shares to separate directories, where to first one has access one user and to second other user. Example:

myDS:/volume1/photos        /home/john/Desktop/Photos nfs rsize=8192,wsize=8192,timeo=14,intr,nosuid

myDS:/volume1/photos        /home/ann/Desktop/Photos nfs rsize=8192,wsize=8192,timeo=14,intr,nosuid

2.  Restart your PC
3. After login to Plasma session by first user (here john) open Dolphin

OBSERVED RESULT
In location bar (left side bar), in "remote" section there are two the same remote locations

EXPECTED RESULT
In location bar (left side bar), in "remote" section should be only present location(s) to which currently logged user has access


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: YES
(available in About System)
KDE Plasma Version: 5.23.2
KDE Frameworks Version: 5.87.0
Qt Version: 5.15.2 with KDE patches

ADDITIONAL INFORMATION