QtCreator not locating Qt6 correctly

I recently reinstalled Qt using the most recent installer but according to QtCreator all Qt6 versions are invalid witha 'qmake does not exist or is not executable' message. Qt5.15.2 works fine. I seems to apply to all Qt6 versions, gcc_64, various android and WebAssembly.

If I run qtcreator from the command line I get:

Cannot update Qt version information from /opt/Qt/6.4.1/gcc_64/bin/qmake: "/opt/Qt/6.4.1/gcc_64/bin/qmake" produced no output: /opt/Qt/6.4.1/gcc_64/bin/qmake: symbol lookup error: /opt/Qt/6.4.1/gcc_64/bin/qmake: undefined symbol: _ZTVNSt3pmr25monotonic_buffer_resourceE, version Qt_6
..
Cannot update Qt version information from /opt/Qt/6.4.1/android_arm64_v8a/bin/qmake: "/opt/Qt/6.4.1/android_arm64_v8a/bin/qmake" produced no output: /opt/Qt/6.4.1/gcc_64/bin/qmake: symbol lookup error: /opt/Qt/6.4.1/gcc_64/bin/qmake: undefined symbol: _ZTVNSt3pmr25monotonic_buffer_resourceE, version Qt_6
..
Cannot update Qt version information from /opt/Qt/6.4.1/android_armv7/bin/qmake: "/opt/Qt/6.4.1/android_armv7/bin/qmake" produced no output: /opt/Qt/6.4.1/gcc_64/bin/qmake: symbol lookup error: /opt/Qt/6.4.1/gcc_64/bin/qmake: undefined symbol: _ZTVNSt3pmr25monotonic_buffer_resourceE, version Qt_6
..
Cannot update Qt version information from /opt/Qt/6.4.1/android_x86/bin/qmake: "/opt/Qt/6.4.1/android_x86/bin/qmake" produced no output: /opt/Qt/6.4.1/gcc_64/bin/qmake: symbol lookup error: /opt/Qt/6.4.1/gcc_64/bin/qmake: undefined symbol: _ZTVNSt3pmr25monotonic_buffer_resourceE, version Qt_6
..
Cannot update Qt version information from /opt/Qt/6.4.1/android_x86_64/bin/qmake: "/opt/Qt/6.4.1/android_x86_64/bin/qmake" produced no output: /opt/Qt/6.4.1/gcc_64/bin/qmake: symbol lookup error: /opt/Qt/6.4.1/gcc_64/bin/qmake: undefined symbol: _ZTVNSt3pmr25monotonic_buffer_resourceE, version Qt_6
..
Cannot update Qt version information from /opt/Qt/6.4.1/wasm_32/bin/qmake: "/opt/Qt/6.4.1/wasm_32/bin/qmake" produced no output: /opt/Qt/6.4.1/gcc_64/bin/qmake: symbol lookup error: /opt/Qt/6.4.1/gcc_64/bin/qmake: undefined symbol: _ZTVNSt3pmr25monotonic_buffer_resourceE, version Qt_6