We are now using Qt 5.12.1 in our application, and after a given time of execution, QDateTime::toString returns results which seems to be generated with the wrong codec.
For example, the .toString("dd/MM/yyyy - HH:mm:ss:zzz"); will return suddenly and continually something like NULEQT/NULETX/STXNULSOH SOHSOH:ETXETX:SOHACK.ENQSTXNUL. We have some Chine guy in the team, and they got a version of the bug with Chine characters. To fix that, the only issue is to restart the application.
It happens in two different applications.