[This only affects people using VNC or xRDP to access our Ubuntu Linux systems.]
We have switched back to the MATE desktop as the default when you remotely access our Ubuntu Linux systems via VNC or xRDP. The desktop is the graphical user interface you interact with when you initiate a graphical session on a Linux system.
The KDE Plasma desktop will still remain as the default for users physically logged in at an Ubuntu Linux workstation.
Digression:
When we migrated to the Ubuntu 24.04 version for Fall 2024, one of the things we tried was to unify the Linux graphical desktop environment by having the KDE Plasma desktop be the default on both local and remote sessions.
Unfortunately, we have discovered a number of issues related to using the Plasma desktop remotely, especially when it comes to a high number of concurrent user sessions on a system. The move back to MATE gives us a faster, leaner, and more reliable desktop for remote Linux graphical work.