Hi, @surfrock66
(Usual disclaimer: please note that I'm just another Forum user here. I'm NOT a Ubuntu developer or Ubuntu MATE developer)
You wrote:
You're (at least) the second person that has reported, here in the "Ubuntu MATE Community", that strange and "funny" behavior of the UN Flag / United Nations flag or logo appearing in the panel area after a Software Update, when the computer needs to restart to finish applying the updates. The first report that I remember about that issue was about Ubuntu MATE 23.10 ("Mantic Minotaur"), in the following discussion topic started by @Sineis_Arilla (Sineis Avila), about 3 weeks ago (on 14th May 2024):
Unfortunately, I don't have a good answer for what may be happening to you, but I've noticed that you (@surfrock66) wrote the following:
"I'm on ubuntu Mate 24.04. I'm using the "Yaru-MATE-light" icon theme, with "Material-Black-Lime" controls and "Green-Submarine" window borders."
In an Ubuntu MATE 24.04 LTS ("Noble Numbat") VM (Virtual Machine) that I have (a fresh install), I don't have that "Material-Black-Lime" option available in the "Controls" tab of the "Customize Theme" window for the Theme "Yaru-MATE-light" (for other people reading this that may not be familiar with "Themes", they are available from the Ubuntu MATE menu -> "Preferences" -> "Appearance") . I only have "Adwaita", "Adwaita-dark", "HighContrast", "Raleigh", "Yaru" and lots of other Controls with names beginning with "Yaru-" (screenshot below). Did you add those "Material-Black-Lime" Controls in some way or did it came preinstalled?