I can't read some dialogs because some letters are replaced by blue squares. Also some icons in the upper right corner of the desktop are replaced by blue squares. If I move the mouse pointer over the icon, the expected icon is shown, see the attached images.
Created attachment 333914 [details]
icons replaced by blue squares
Created attachment 333916 [details]
icons replaced by blue squares with mouse pointer
Created attachment 333924 [details]
The issue disappeared after restarting the gnome-shell.
After the next login I have again the same issue.
It should be clear that without any error message, nobody can help here. I personally cannot confirm this.
please provide more technical information, like graphic card and drivers you use...
Also check with 3.8