QDate::fromString() memory leak in MacOS

My MacOS application frequently uses the QDate::fromString("20220608","yyyyMMdd") function, and it is found that the memory leak is serious. So I try to write a simple example, calling QDate::fromString("20220608","yyyyMMdd") in a thread run(){while(1){...}}. Sure enough, this function is the problem, and the memory is always increasing