Question on demand calculation?

Hi, so I’m playing in Quimby VI and I’m having trouble filling up a certain flight for my E195s. My flights from STL to MDW are being very spotty in the way they’re filling up-there have been some days when they’re full but lately they haven’t been at all. The return trip MDW to STL hasn’t really had a hard time filling up. My price is lower than the default ($97, default at $99), I have no competitors, and my service is packed on nearly every other route even with competitors. Additionally, I had started late on Quimby V and even with competition STL-MDW was always full and my cash cow. So what gives? If someone could help me understand this conundrum that would be great, thanks

Maybe previously you had a lot of connecting pax to a destination which you don't offer now?

competition as well could be a factor?

Also the demand on the server grows over time, maybe what you compared with was a full demand and now you are comparing it with a fractional demand ona new server.