UI update in an EventListener: "UI Shared state was accessed from a background thread"

Support
#1

Hello,
I want to update a badge text upon receipt of an event, but I’ll get the error in the comment:

    @EventListener
    fun onInvoiceChanged(event: InvoiceChangedEvent) {
        // FIXME UI Shared state was accessed from a background thread
        // item: SideMenu.MenuItem
        appUI.access {
            item.badgeText = "test"
        }
    }

I already tried to obtain the UI in different places: BeforeShowEvent, InitEvent, directly before usage…

            appUI = AppUI.getCurrent()

The funny thing is, it works sometimes. Other times it doesn’t an I get the beforementioned error. Any ideas?

#2

The event class:
class InvoiceChangedEvent : GlobalApplicationEvent, GlobalUiEvent