Sorry, this is not a "new" pain or irritation. And step-ups, which are essential for old-age strengthening, hurt much more than squats.
BoneSmart is very anti-activity. Although I don't believe in too much exercise immediately after surgery, and slow and steady is good, I do believe one should be able to get most of your joint use, without too much pain and stiffness, after 7 full months post-surgery. If not, something is wrong. And you need to advocate enough for yourself to get it fixed.
I have had arthritis since my early 20s (1977). I had a spinal fusion after a ruptured disc, and after a month in traction, when I was 24. I learned to walk again, and yes, finally was able to walk without dragging my foot in 9 mos to a year (mostly gone in 9 mos unless I got tired, then it dragged). It did take me another year to be able to raise up that leg on my toes. But I kept up until I could although most of my right leg is still numb.
I had the metatarsal joint of my right foot operated on to remove bone spurs and damaged cartiledge 3 years later. I have had hand surgery twice, the first operating on multiple fingers. Most of my finger joints are all bone on bone.
I had a spinal refusion in 2005. They broke it where it was fused originally, put in a cadaver bone piece as a spacer, put in 2 titanium clamps, 4 screws and more cadaver bone around all that to stabilize it (so I was not in a steel back brace like I was after the 1st fusion for 6 months). I went back to work after that one in 2 weeks and the pain was mostly gone in 3 months.
I guess I expect a lot, but I should have a knee that doesn't "thunk and crunch" and feel like a "peg-leg" when I walk. And based on all my previous joint surgeries, I don't think that is too much to ask. If Medicare won't pay for a revision if it keeps up, then I will. I have no desire to be an invalid.
Sorry, but I'm not ready to be in a rocking chair (but don't rock! too much activity!), with a BMI over 40, and just be grateful that I can putter around very, very gently but not actually DO anything.