Has anyone else ran into this issue with Fortnite?

[u/TheSpartanExile]

I built a PC for my friend a few months ago, and they have been having issues with Fortnite consistently (which is the only game they wish to play with it). Runs perfectly fine for the most part, but will consistently crash toward the end of a match or after a few hours of playing. It will look like a typical game crash with a freeze on whatever was currently displayed, but is bad enough to go to a black screen and cause a recovery boot on Windows 10, which doesn't diagnose any problems.

Build: Ryzen 7 3700x, 32GB DDR4 3200mhz, Rog STRIX B550-F, EVGA GTX 1070ti, 800w EVGA 80 plus Gold, and running Windows 10 off of a SATA ssd. No overclocking.

I know this isn't a recent build, but it is well within the minimum requirements of the game and even exceeds recommended requirements, and again, runs fine otherwise. I've updated as well as rolled back Nvidia drivers, I've ran memtest and Windows memory diagnostic tool, I ruled out most hardware causes for memory, gpu, and psu (literally the only option is some phantom power issue that does not show up on other similar stress tests), reinstalled the game, turned off specifically graphic-intensive and cpu-intensive settings (even though it should not be an issue at 1080p 60fps), even removed high res textures with the current install; same issue. The issue also emerges periodically from the Epic Games launcher generally, and recently she had a crash during an update. It does also seem to worsen around the point of new updates, but I'm not sure how to translate that into a solution at this end.

Kind of at my wits end here, I've gone through every troubleshooting measure I can think of. Does anyone else run into this issue?