Open pdfs in Preview instead of Adobe Reader

**Before** macOS Ventura. I'm using Preview as standard application to open pdf files, and have Adobe Reader installed for occasional use. **Problem** For the past week, whenever I double-click on a pdf file, it is opened in Adobe Reader. All pdf icons in Finder have changed from a Preview icon to an Adobe Reader icon. * I have tried several times to right-click on a pdf file and state that Preview should be used as standard application. However, the next time I double-click on a pdf file, it's opened in Adobe Reader again which seems to be set as standard application. * Sometimes, after right-clicking to open a pdf file in Preview, it does not open at all. I then obtain a message ``Impossible to open ".pdf" because this application comes from a non identified developer. macOS cannot verify that this app does not contain malware. AdobeAcrobat has created this file today at . `` What could have happened that caused this behaviour and how can I fix it?