Interesting, so my RT was set to SAFE. I switched it to UNLIMITED (it was already set to “dynamic” under “playback quality” subsection), and the red bars turned a faded orange, allowing me to view my clips in the timeline. Thank you!
That said, this tweak is unnecessary on my iMac (as I normally use Safe RT, with dynamic playback quality, and it is in fact set to that, without any red bar issues). Any idea why?