Try uninstalling and reinstalling Dashlane.
If Safari is slow, stops responding, quits unexpectedly, or has other issues
https://support.apple.com/en-us/HT203353
Section: Manage Extensions
https://support.apple.com/guide/safari/use-safari-extensions-sfri32508/mac
If this doesn’t help, please run EtreCheck and post the report here if you can .
https://etrecheck.com
Click “Free Download” button, open Downloads folder, click on it to open, and then select ”Open”.
Click on the bouncing EtreCheck icon in the Dock.
“Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.
Click “Share Report” button in the toolbar, select “Copy to Clipboard” .
Paste it into the reply.