I'm having the same issue! I attached my park. My park count has stayed around 1300 for the last 45 minutes, even when I've been expanding like crazy. I'm constantly monitoring the rides so that I decrease their cost when the guests complain. But there's not much complaining, and I'm adding new rides and the overall count doesn't increase. I've noticed this for a few scenarios. I can't detect any other issues. I've been playing this game for 10+ years (never gets old) and I should have WAY more people than this. BTW this is on Windows 10, 64-bit version.