If you exited a Tomb of the Erased and used portal then clicked on it, it will warp you at the beginning of the Monolith of Fate instead of the reward area. Rewards and effort wasted.
It’s like you clicked on the portal but still re-entered the Tomb of the Erased behind the portal, causing it to bug out.
It happened several times already and I thought it was just because “I finished the tomb” already, but some of my runs I was able to take rewards inside the tomb as well as portalling back to the intermission area. I was doing Ending the Storms timeline when this happened again.