Hi Frank,
I am using Xcode 11.1 on Mac OS Big Sur. The reason for using 11.1 is that it is the last version that includes Platform API 10.15 which is the latest version supported by Qt5. The previous build was done with the latest Xcode.
It is compiled with Qt 5.15.2 and targeting MacOS v10.13 (QMAKE_MACOSX_DEPLOYMENT_TARGET = 10.13)
73 Phil M0VSE