If it it is more than a few days, you may have to fill out a missing stay credit report.

I never had to do that until this year. I had a stay in March (1 night) that didn't post after a week, so I requested credit and it took until September to post.
My last stay also didn't post a week after checkout, but it only took about 12 hours after I submitted the missing stay credit to get it posted.

So, most likely you just need a good 24-48 hours after checkout for a stay to post and status to update, but small chance of there being some delay....