Maybe Shiboken issue ( ? ).
Simple QObject creation and deletion causes mem leak.
9 line example code included.
I have tested it on Ubuntu14.04 LTS, Win7 32bit, Win7 64bit on PySide2 v5.11.2 and I believe it is general problem.
I believe this can relate with other mem leak issues:
Even this matplotlib interactive demo suffers from the leaks (tested on matplotlib 2.2.3).
Just add this 3 lines at the beginning of the example to ensure you use PySide2 for it: