Issue with controlbar on Ubuntu - Warning: Error in iconClass: could not find function "iconClass"

[D3SL]

When trying to build an ubuntu 20.04 based docker image using the control bar causes an infinite loop of this error when trying to start the app. I don't get this error when testing on my windows machine locally, which makes me think it's version related since the marutter repo isn't always up to the latest CRAN version. I've got R 4.1.2, ShinyDashboard 0.7.2-1, and ShinyDashboardPlus 2.0.2-1.

Warning: Error in iconClass: could not find function "iconClass"
  83: dots_list
  82: div
  81: controlbarItem

This is the ui code I have for the controlbar so far:

#Right Sidebar-----
   controlbar = dashboardControlbar(
     collapsed = TRUE,
     controlbarMenu(
      id = "controlbarMenu",
      controlbarItem(
        "Tab 1",
        "Currently Unused"
      ),
      controlbarItem(
        #icon = "paint-brush",
        title = "Utilities",
        h5("Viewport Dimensions"),
        verbatimTextOutput("dimension_display")
      )
     )
   ),