Problem on MacOS 16.5

I just upgraded my Macbook Pro to Sequoia 16.5, and Nextcloud does not work anymore, it alwayus says “The application nextcloud.app can’t be opened”. I removed the nextcloud preference files, reinstalled the app to its latest version (3.16.5) but to no avail. What can be the problem here?

I use nextcloud to sync a number of folders to 2 nextcloud servers (not the same folder to the two servers of course) and it is of essential use to me.

Please help, does anyone has the same problem wit the latest macOS?