After editing "Initial CMake parameters", I get SOFT ASSERT: "type == "UNINITIALIZED"" in console

If you open a CMake C++ project and add extra lines to Project mode -> "Initial CMake parameters" textarea, then I start getting the following warning in the console (but no harmful effects that I've seen):

SOFT ASSERT: "type == "UNINITIALIZED"" in file /home/qt/work/build/qt-creator/src/plugins/cmakeprojectmanager/cmakeconfigitem.cpp, line 162

Steps:

• Clone and open https://github.com/KDE/plasma-workspace or https://gitlab.com/exotracker/exotracker-cpp or another CMake project.
• Added new definitions to Initial CMake Parameters (eg. -Dfoo=bar).
• The warning is logged to the terminal every time I close and reopen the project, or switch to a different session and back, or restart Qt Creator, or click menu Build -> "Run CMake" (1 or more warnings), or click Project mode -> "Re-configure with Initial Parameters" (more than 1 warning).

The warning text is identical every time it appears. It doesn't seem to cause any negative effects as far as I can tell.