2020r2 websession messages do not show on backgrounds

Moving from 2019 to 2020 now includes messages that appear when a user disconnects or loses connection. Great idea, but the text doesn’t show when I have dark background. I can’t seem to find a way to stop those message appearing even if I set the message string to blank.
Scenario… I have a simple wallboard app that displays HTML data in a webhtmlviewer… that display is black so it can highlight the data… when I disconnect, a white message box appears but is white text on a white background. (same happen if I change to blue background. White background is fine however.
Any work arounds ?