Same thing here (since day one..), currently 6.6.3 (840) MAS running on macOS 11.4 (had this issue with previous versions on Catalina as well)
- Sync via Webdav seems to cause extreme lagging when updating/editing and copying entries as syncing seems to "block" the app
- VERY slow search in the Main Window
- VERY slow search in any Browser Extension
- Browser-Extension-Window often needs to be closed and re-opened in order to show matching elements
Total number of vaults: 1
Enabled to show all counts for the sidebar: No