I had two stays (one from November 2018 and one from early this year) that had failed to post. I have submitted missing stay requests using the online form at least twice (it might have been three times). But I received no love from those attempts.

So, this morning I explained the situation in an email to the Diamond line ([email protected]), and attached relevant supporting data with the email (as I had done previously via the online form).

Hilton responded to me within about ONE HOUR from my submission of the email - both issues resolved. The missing points and the updated nights count were already resolved in my account when I logged in to check after seeing Hilton's response email in my inbox.