Yes, recovery isn't a linear progression. You will get these periods when your progress seems to grind to a halt. I don't call it stalling, but a period where your knee is consolidating the progress it has made, before moving ahead again.
From now on, you will notice little achievements, rather than big ones. Celebrate them all! I saw a few posts back that you were able to do a full revolution going backwards on the bike. That's progress, and one day you'll find you can do it going forwards as well.