It usually takes 2-3 weeks for a stay to post to your account. If it has been longer than 3 weeks, please fill out the information below and click submit.
https://www.hiltonhhonors.com/Servic...ices.aspx?p=sr
Sometimes it really does take a few weeks to post -- but they almost always post automatically.
If it doesn't, just use the form linked above. Unless for some reason the hotel has no record of your stay, missing stays are credited within a few weeks of submitting the form.
I think I've only ever had to do this once.