Something seems to be triggering scanning constantly and Qt Creator freezes all the time.
During one of about 15 minute freezes, debug messages from Qt Creator seems to show things like this for different files:
This continues for a long time for many files seemingly for QML files from Qt installations (mingw and msvc), then few messages from clangd, and then similar to above continues again. I can see that same file names for the same import and version seem to repeat few hundred times during this.
Qt Creator is also showing "cppcheck", "Parsing C/C++ Files", "Parsing QML Files", "Scanning QML Imports" indicators in the UI at least.