new render cache quirk

Since I am waiting for my red line to become blue, I will share another bug (I think) than may help sort out "the non persistence of render cache problem," on older projects.

I have developed this habit of muting, pressing play and posting on the forum till my line turns blue, and rarely getting any work done on this specific project.

Today, out of the blue (pun intended) I open said project and see with joy some blue lines had carried over from my previous session, where I had to leave and forgot the project playing in the background for many hours. Helas, this was merely an illusion. The clips were offline, even though I could play them in the source window.

When I cleared all cache, which I should obviously do at the start of each session since it is not persistent, the clips reappeared.

Obviously the clip in the timeline points to the cached clip when the line is blue, but for some reason it isn't linked to it and this is obviously different behavior from when the clips show up as red, even though there is a rendered clip, but the clip in the timeline doesn't point to it at all. I still think the existence of keyframes on some clips plays some role in this behavior.

This is on 17.2.1. build 12 with 462.59 studio driver.

I dare not upgrade to 17.2.2