I'm not qualified to give actionable advice, but strongly consider the following and seek info from actual sources if you think it can apply.

Sometimes use injuries can be a little insidious in that they don't seem severe accept when being exacerbated by exercise, but bit-by-bit they can become something that is difficult to heal from. Better early than later.

You are getting some good advice about relieving stress on the back of the knee by engaging the quad and keeping a soft bend, etc. Consider also giving the unhappy tissue back there a few weeks to heal without enduring the stress. Sometimes stopping for a bit and then returning to training can help the body heal.

I endured a dull ache in my hip flexors while training oly for a long time. I would foam roll, stretch, work on form, warm up etc. in response to it and in order to mitigate it. It ended up slowly growing into an issue and one day I felt something sharp. Took me several months of PT to calm my angry hip flexors down, they had been pretty beat up by then and were inflamed.

It turns out I could have fixed it at any point along the way with a few weeks off with some light stretching. But I let it slowly turn into something bigger. As soon as I laid off and let it heal, I went right back to training the exact same way and have been fine for many years now.

Sometimes your tissue just needs a little space without being trained.