Stay firm with PT and don’t do anything that hurts. They are not the authority we are led to believe. You are allowed to say no!
It’s your knee/home, not theirs, and you have the final say what you do.
Also keep in mind, it’s not exercising that gets our range of motion back, it’s Time:
Time to recover.
Time for pain and swelling to settle,
and Time to heal.
Our range of motion is right there all
along just waiting for that to happen so it can show itself.
In the general run of things, it doesn't need to be fought for, worked hard for or worried about. It will happen. Exercise as in strength training is counter-productive and in the early weeks does more harm than good. Normal activity is the key to success.