Weird Knee Injury?

[UnderRated700]

Almost a month ago, getting back to the gym after 3-4 months of not training I experienced a weird "injury" in my knee that I wasn't able to diagnose.

I believe it happened from too much stress on the knee, including a lot of walking, standing, stair climbing, cycling and heavy workouts.

What I felt?
- No pop, no pain, no strain - just something I felt after the second leg workout that week.

Symptoms I had or still have:
- Wasn't able to fully lock my knee - It got a lot better now but still not fully (I get to around 90%)
- Unstable knee, meaning when I placed my hand on the knee, I felt the tendons snapping and all sort of unpleasant sounds every time I extend the knee.
- Blood flow feeling in my knee and especially in the lower quads. (it didn't feel numb or tingling but very strange feeling to describe)
- I want to specify that pain was very little to none. By very little maybe only when I squatted deep or did some weird knee movements.

At first I thought it was only inflammation and that it will go away. After a month of recovery, very little leg weightlifting and some rehab work, it did get A LOT better but still not perfect for me to start lifting heavy again.

Any information will help, I am considering doing an MRI soon and checking it with a PT.
Thank you!