Pep's

Hello, On affinity publisher 1.8.6 on Big Sur I have a problem with the font setting and the preview. When I launch the app I can have a preview of the highlighted font but when once I've selected a font and I want to choose a new one for the same text I have no more highlighted font and preview and I have to relaunch the app to find back all that. For instance, on the screen shot I put on this topic my cursor is on "comic sans ms" but nothing happens. Is this a known bug ? Thanks