S10+ T-Mobile update rolling out Today

I'm wondering if it can even be fixed with a software update or are we stuck with flawed hardware.
Not happy having a $1,600.00 phone with a bad FPS.

Not completely. It will get more reliable as Samsung gathers feedback from users. But just like most new tech implementations, it will be perfected in future models. Just like Apple didn't wait until Face ID worked in low light before they started charging 1,000, neither will Samsung.

But the fact that not every user is having major issues with it, means it needs some tweaking. If it were strictly hardware, no one's would work.