Raptors kept the hydraulic power steering after the other f-150s went to electric so there are some upgrades available. Howe sells a performance pump and RPG (raptor performance group) sells a larger reservoir to prevent aeration. In reading it looks like raptors had an issue with the power steering fluid getting hot and aerating which would lead to pump failure.
In your case a similar issue with hot fluid leading to pump failure could have caused issues with some of the valving and internal seals in the rack causing it to fail. The other possibility is that you are simply seeing the limits of a rack and pinion steering. Your truck has only been lifted for a little less than a year so if you have another similar failure it might be time to consider a solid axle swap.
