I had the opposite problem - great ROM, but in spite of diligent exercises only achieved full extension after 4 months. So I also walked sort of lopsided for a long time. It helped some that I kept telling myself / my brain, that my TKR knee is just a regular knee.... and to use it as such. Mental acrobatics, but even if it sounds weird, it did work to a certain extent.
Now - after almost 7 months post surgery, I still exercise the knee most days. Not sure if this is necessary, really, but I don’t want to regress.