I can confirm this issue as well. RAM usage start normal and slowly but surely go up. Once it reaches around 7GB it “dumps” the memory but doesn’t release it, eventually it will do this again, and again until it finally uses all available system RAM and crashes. I have seen it say I’m at 95% usage yet Unreal is only using around 2GB and no other program is using a significant amount of ram.
I am using 4.10.2 on Windows 10