I very recently bought a used Pixel 6 with a replacement screen, not thinking too much of it. I even made sure that the screen looked good during pickup.
One thing I missed though, was that apparently my Pixel doesn’t have a fingerprint sensor anymore. I did some research, apparently it’s quite easy to break the fingerprint sensor (or some places simply just don’t include a sensor in the repair?) when replacing the screen.
Today I also noticed (through Show refresh rate in developer options) that my screen will only do 60 Hz as well.
Also I have stupidly high battery drain, I’m not 100% if that’s related though.
Long story short, learn from my mistakes and either don’t buy a used phone with a replacement screen or carefully test all functionalities associated with the screen, mainly high refresh rate and the fingerprint sensor.
It’s likely an aftermarket screen. I got my screen replaced on my Pixel 7 Pro, the fingerprint sensor never worked again. It also had a lower refresh rate, just like yours.
uBreakiFix is an authorized Google repair place if anyone needs this done but doesn’t want to themselves.
iFixit has OEM screens for a relatively good price, they even have the fingerprint sensor pre-installed, so no transfer of the old one is necessary.
I replaced the screen on my Pixel 7 a while ago and it took roughly 2 hours, most of that was scraping off the old nasty adhesive. Color quality, refresh rate and everything else was the same.