I had a torn ACL that was replaced from donor tissue also small tear in meniscus.

Can read the whole thing here if you wish.

https://www.newagtalk.com/forums/thread-view.asp?tid=911549

Outpatient rehab got shut down early due to covid before I had full range of motion back as well. 

Surgeon said figure a year to get back to normal he was not wrong unfortunately.

He cautioned me that in my situation where it needed to grow around the graft the most critical time was right when you could walk without a walker or cane. He said that was the weakest point and where the most damage could re-occur  especially if twisting or stepping in a hole etc. That happened to be right at planting time for me.

It's hard to be patient and cautious but you surely don't want to undo the repair.

This was different than whole knee replacement which seems to progress more quickly. 

Good luck !