GUI "disapears" after reopening

I run Vital inside of ardour on a linux mint os.
When i use Vital inside an ardourproject everything works fine.
But when i close the Vitalwindow and open it again. The Gui is not displaying everything. Instead of the Knobs, faders and numbers, there is just boxes and i have to click and change the values of these so that i can see these elements again.