I have the same problem. Massive shame as I just was finally able to diagnose that the GPU drivers for the Gigabyte 4070 Super cards are actually broken on all UE5 games, and especially on Fortnite.
Software RT/Hardware RT:
[“An error occurred: Sorry, new users can only put one embedded media item in a post.”]
[“An error occurred: Sorry, new users can only put one embedded media item in a post.”]
Yes. These are different screenshots, with different settings. Hardware RT is just completely broken. 
This did not work: https://www.epicgames.com/help/en-US/c-Category_Fortnite/c-Fortnite_TechnicalSupport/what-can-i-do-if-my-pc-crashes-with-hardware-ray-tracing-a000092489