I had a similar issue where the hit result was 0 on/after release. For some reason, it is not a good idea to call hit result under finger on action complete/cancel for a touch input action. I assume its position is simply reset, and we don’t have access to it anymore. (I have it reset on the last triggered as well… So, i have to store the previous one)
I worked around it by storing a hit result in tick and using that result at release (because I was already doing that).
Edit: This is still true in UE5.5. I had the same problem again, only to find my own answer 