[CRASH] Game crashes in loading screen

Hello, this is what is happening to me sometimes: I get to the loading screen from champion select, everything seems alright at first, but when the progress bar reaches 100% the game gets completely stuck, I can tell that from the "green circle with ping" in the top right corner (it freezes). I cannot get to my desktop via Alt + Tab or Windows + D anymore (only the taskbar shows up, but i cannot access any other program, e.g. task manager, since the loading screen is still taking up my entire screen). Furthermore, the game refuses to quit after hitting Alt + F4 several times. This does not happen often (about once in 50 games or so), but when it does happen I usually end up being labeled "Leaver" in my game history, because my teammates remaked, before I had the chance to join. This is unfair, why is it not being treated as "Loss Prevented"?

It is definitelly NOT a connection problem on my side, I am connected to the internet for the whole time (I can see that on the taskbar, also my network is running just fine on other devices). It is also probably not a hardware problem, since I experienced it on different devices.

The main issue I see in this is the fact that the game is considered a loss and I get a leaver status for it (especially when it is a ranked game).

OS: Microsoft Windows 10 (64-bit), version 1903 (build 18362.418)