The build speed of jom.exe v1.1.4 is much slower than that of v1.1.3

I have been using qt-creator-10.0.2 version, because the jom.exe in 10.0.2 version has a faster build and compile speed.
I found that since qt-creator-11.0.0, the jom.exe version has changed from 1.1.3 to 1.1.4. The new version of jom.exe has slowed down the source code build and compile speed, and it is much slower.

For the same source code project, the build speed of jom.exe v1.1.4 is 5 to 10 times slower than that of v1.1.3.

Take this open source project as an example:
https://github.com/githubuser0xFFFF/Qt-Advanced-Docking-System
Qt Creator v14.0.1+Qt5.15.2+vs2019x64+debug+jom v1.1.4
When you click the "build project" button for the first time, the build speed is normal. After waiting for the project to be compiled, click the "build project" button for the second time, and the build speed is very slow.