1 . Now it's OK, i can't use RealVNC or Remmina with my laptop, but the web browser interface works. And I finally connect to remote desktop using VNC on Ipad. Everything is ok now.
2 . The first times, the location was always asking for GPS location (i don't have a GPS dongle in the Rpi4, only a RTC) but after a couple days, the default location is now the one i set in the database of Kstars. That's perfect for me.