plotOutput() and webGLOutput() issue

[Berecht]

I am trying to have a simple plot output and a 3d plot output in the same app and switch between them with a selectInput. A weird blank square is appearing above the 3dplot or the normal plot, depending on order in the UI mainpanel

      plotOutput("PCA1"),
       webGLOutput("PCA2")

Google chrome, inspect element:

"

"

          webGLOutput("PCA_plot"),
      plotOutput("PCA_Bar")

Google chrome, inspect element:

argument is not interpretable as logical