It’s not just you. Going on a small mini rant here:
Why can you guys not get Preview to work?! It’s not higher math, you know. You have a bit of the original on the left, then play the segment, in the adjacent window pane, only processed. This is child’s play – or should be, rather. And remember 2.6.4, where you could even do something as radical as click back in the processed timeline, and see the result? (= very useful, to see whether you’ve chosen the right settings for your video, by checking various processed sections). And don’t give me ‘difficult.’ It was possible in 2.6.4 just fine. So, whoever you let do the Preview in 2.6.4, hire him back, and let them fix the current incarnations of your software. Because currently Preview is severely broken: half the time it just shows the original; and where the original is supposed to be, it says 3840x2160 as well (although that’s just cosmetic), The other half of the time Preview shows something (but never back on the timeline), or TVAI just outright hangs when the clip ends. /rant
I cannot stress enough how important a working, side-by-side, Preview is; and one where you can ‘preview’ the processed results earlier in the timeline too. All new fancy models are cute and all, but of little use to me if I can’t do easy Preview tests (and, again, see earlier processed data too). Even on my i9 12900k + RTX 4090, processing a full blu-ray can take up to 8 hours. Preview is essential: if not for my own sanity, then for my electric bill.