It depends. Did your employer withhold New York state tax?
New York follows the convenience of the employer rule, meaning if you are considered to be a Buffalo-based employee who is working remotely for your own convenience, then you are liable for New York tax.
You can claim a credit on your PA return for tax paid to NY.
If your employer withheld NY tax and you never set foot in a NY office, you can instead file for a refund of all tax. You will likely get audited, in which case you can cite several court cases in your defense.
Read the discussion by @kristinelbly in I work for a NY company, remotely from NC. I spent 1 day in 2017 on site, but my W-2 has full salary in the state earnings boxes for both NC and NY
Thanks @ErnieS0 for bringing that thread to light here.
If your employer is withholding, and you are expected to be a 100% remote employee, that's incorrect. If your employer expects you to visit the office occasionally, even though you have yet to do that, they are correct.
I actually work for a Buffalo based firm, and well known locally. If you're really 100% remote employee, happy to have a brief discussion with your payroll department and send over some guidance their legal team can review (assuming there is no conflict of interest with your employer that would preclude me from having that conversation).