If you're open to docker options, I've used and recommend ArchiveBox. It supports using a login to rip sites, and you can set it to rip once or on a schedule, etc.
I think they have a desktop app version in the works if you were looking for a more of a one-time approach.
I'd add that it might be worth checking out the JavaScript console as well (F12 > console in most browsers), in case the problem is with the login page
Another vote for Joplin here, but I prefer to host Joplin server for synchronization because it's much faster than NextCloud.