How to reset the app icons? - They get substituted by a default icon

Sometimes, the app icons just "switch" to an android icon: " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> For example in this screenshot, the Dropbox (center row in the left) icon is an android icon. This happens to me from time to time with many different applications. The bad icon works properly: It still opens the application normally. If I grab the dropbox from the all-apps folder and drag-and-drop a new shortcut, it displays correctly: " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> If I remove the bad icon, and leave only the correct icon it seems all normal: " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> Questions === 1. Why does this happen and how can I prevent it happening in the future? 1. Is there any way to "reset" all the bad icons in one shot?