In this scenario, the reported behavior is observed in NET 8. The same behavior is not reproducible in .Net Framework 4.8. When the map is zoomed max out and we try to pan the view, missing tiles appear and the performance is very slow. Additionally, in the output tab of VS, we can observe some exceptions:

When Windows 11 Dark themes are applied the Legend items panel back color is not changed. This behavior is observed in the following themes:

• Windows11Compact11Dark
• Windows11Dark
• Windows11HighContrast