What theme are you using? It looks as a CSS caching issue. If you upgraded from Radzen.Blazor 4.x to Radzen.Blazor 5.x recently check this thread: Upgrading to Radzen.Blazor v5.0
What theme are you using? It looks as a CSS caching issue. If you upgraded from Radzen.Blazor 4.x to Radzen.Blazor 5.x recently check this thread: Upgrading to Radzen.Blazor v5.0