I started this thread and noticed that my post count was 352. I added three additional posts on that thread and my post count stayed at 352! Shouldn’t it have risen to 355?
I can’t answer this, but right now, your post count says 353, while when I do a search on your posts, I find 354 of them. Similarly, my post count says 578, but I can find 579 of them. I haven’t tried on anyone else, but I wouldn’t be surprised if it was the same.
As for why it didn’t increase when you wrote those three posts, maybe a thread with three posts by you was disappeared at the same time? Or would that in fact even influence your post count, given that they wouldn’t be deleted, just moved to an invisible forum?
Yeah, I know, I’m not very useful here. 
The post count does not automatically update on a non-refreshed page for one thing. As for it apparently not keeping up, I don’t know. I haven’t really paid a lot of attention, but I also have not noticed this problem when I did glance at my post count.
The database software does not treat all activities equally, it prioritizes. Posting takes priority over updating individual stats. There is an internal queue for each category of things to do, and the low priority lists can take time to catch up.
There are prior threads around here (not sure what key words to search with) where people noted that their counts would catch up after a few hours.
Hmm… I wonder if we can force something more specific by trying?
Texas Houston Austin Dallas Amarillo
Yup, pardner!
This was the ad list after that last post:
Find Texas Attorneys
Find any Texas attorney with the State Bar of Texas member directory
Austin Texas Homes Sale
Search homes for sale in Austin Texas. Over 12,000 listings. Free!
Austin Texas
Browse Listings, Photos, and Maps Compare Prices by Neighborhood
Austin Texas Real Estate
Only Austin broker with over 20,000 aerial photos and virtual tours.