@Ste74 Alright, everything seems smooth so far... except for a small issue with theme.
I have noticed this in the Budgie edition as well, but I did not really pay too much attention to it since I changed back to the default theme quite quick.
If you notice the screenshots you posted on both Budgie and Mate release, you see 'dashed lines' around the menu. It is present in both the DEs. This 'dashed lines' appears elsewhere too, in the control centre, the theme changer,... basically many places and it looks out of place (see attached screenshots for reference).
I naturally suspected the theme and noticed that some themes have this issue while others do not.
Theme changed on Arc:
Theme changer on Vertex:
Theme changer on Adapta:
Notice the dashed lines on the outline of the window? It appears on other applications too, like Caja.
Following themes have the dashed lines issue:
- vertex and vertex maia
- arc and arc-maia
Following themes DO NOT:
- Default MATE themes
- Adapta themes
It is probably an upstream issue, but I am reporting it here so you can take a look at it