I can't see some icons on ubuntu 22.04
which ones are you missing?
Hello
Looks like you are speaking about the icons in the indicator.
Believe you might have to change icons in the theme you are using
Note: mark down what settings you have to be able to reset after testing.
See images: second shows effect of me changing icons in 4
Edit grey box in indicator is shown on my system based on my theme choice your background may be the color used in your theme choice.
Did some more checking and new picture shows using the Humanity Icon set (is included in my UM22.04.2) as shown on page for Human GTK3-Traditional theme shown here
https://www.mate-look.org/p/1309630/
and imagine in the issue in your post here:
https://ubuntu-mate.community/latest
Image is same as above with Humanity Icon set chosen