We have for many years built Java applications accessing Postgresql databases using NetBeans. We run these applications on Mac OS X, Windows 10 and Debian.
Around the time of an upgrade to Mac OS Catalina release 10.15.7 (early Sept 2020) when running on recently purchased Mac Mini all JDBC access to remote servers started failing (usually a timeout). Accessing 127.0.0.1 using postgresql-9.0-801.jdbc4.jar works but accessing the same machine using its external IP address failed. We have built a test application that fails on Mac OS Catalina 10.15.7 on the Mac Mini and runs as expected on Windows 10 and Debian 9.8 both running on the Mac Mini as a Parallels Virtual Machine. It I realise this is not a NetBeans issue, but if any other NetBeans user has encountered this business critical problem let me know and I will share my test program, my test results and a list of things not to do whilst searching for a solution ! Regards David Gradwell
