All windows freeze after a while

I have an application which there is a main window and child windows. Using the main window, you can open child windows. All windows are written using qml. The application communicates with the server using a QWebSocket. Everything that the client receives and sends is written to the logs.
We see a problem that after some time (always different and under different circumstances) our windows freeze, the main window and child windows too (that is, all window elements stop updating). But the logs continue to be written.
We tried to see this problem on another machine with Windows OS, as well as on several other Linux OS machines, but the problem is visible only on one machine. I attached the characteristics of this machine below. What is characteristic, we see that when we turn off the integrated Intel HD Graphics 4600 card and use only Nvidia GeForce GT 740M, the problem disappears.