Newer heating and air systems, especially if you had your system replaced recently. A lot of newer systems are meant to have lower airf flow as long as they're keeping temperature in your home. They may have a variable speed indoor fan motor or even an ECM meaning multi- speeds. There's going to be times when it's just barely running depending on what mode it's in, and depending on what type of system you had installed, it may be doing exactly what it's supposed to now.

I Will say if it was installed and it's low air flow and it's not keeping temperature, something might be wrong, right? But all in all, if your old system was kind of blowing the curtains back and your new system no longer is, it's very possible. as long as that system is keeping temperature despite having lower air flow coming out of that vent, it's very possible that that system is operating exactly how it's supposed to.