Blackmagic files and program mystery

One day we filmed with Sony FS7 and Blackmagic pocket 6k. Sony recorded its own video files, and BMp6k created BRAW files.

We opened both files in Davinci Resolve and created proxies from them. Not a single problem with Sony files. Some problems with BRAW files. Now, please help me understand something:

BRAW file number 1 was 9 minutes long. BRAW file number 2 was 12 minutes long.

File nr 1 has picture and audio. When the proxy was created, the audio got cut at 3 min time, leaving the rest 6 minutes muted. When we reviewed the original file it also appeared to have a missing the rest of the audio after 3 min even when we were 100% sure we recorded the audio and monitored it for the full 9 mins.

File nr 2 created a proxy that was 7 min long. The original file is 12 minutes, but the created proxy file was shortened by 5 mins.

All this happened 24 hours ago. We started to investigate, restarting the Davinci Resolve multiple time, slept, woke up, ate breakfast, went to gym, restarted our Macbook Pro m1.

Today, suddenly, File nr 1 shows audio for the full length. We generated proxy, it is all fine. We also created new proxy of file nr 2, and now it is 12 minutes long.

What the hell is going on?! It feels like Davinci Resolve is buffering files, but does not give any kind of indicator that some files are not buffered/build/uncompressed completely. Also, this buffering does not take minutes or hours, but a day!

1. Why video format that is made with Blackmagic camera to Blackmagic video editing software produces such issues?
2. Why Davinci Resolve doesn't tell us "Don't create proxies yet, I'm not yet ready!" or "There is audio on this file but I can't play it yet. Go grab a coffee and come back in 30 mins."
3. How can we ever be sure if the braw file of 15 min length we manage is actually, like, really 15 minutes and not 27 minutes after we start the software next week?

looks you record in HFR (off speed) mode on the 6Kpro

Which hardware (CPU, GPU, RAM, disk I/O speed)? What specific version of Resolve? What OS? What source file codec? What timeline resolution? What framerate? How does your drive rate with Blackmagic Speed Test? Which GPU drivers are installed? What proxy format are you using?

If it were me, I'd create all the proxies manually, target them to a specific drive (separate from the original material), and embed timecode and all the shot information (camera name, reel/card number, shoot date, timecode, etc.). Make absolutely sure the filenames are 100% identical to those of the original material, except fo course for the extension. I'd edit with those, then when I was finished, relink back to the camera originals and finish the show.

All of this CAN work, but you have to be very careful that your cache files aren't getting in the way. With a powerful enough system, you can eschew almost all caching and just use the straight files without a problem.

just use the straight files without a problem.

I do this even with pretty old hardware.

i5 2500K
8GB DDR
GTX 960, 4GB of VRAM

Although it doesn't answer for every bizarre occurrence noted above ("maturation" of the files after 24-hours?), the only plausible explanation so far, per Mark Foster, is that this material was mistakenly recorded with the "offspeed" mode and that its fps metadata is confusing proxy creation, and clip timing. Recovering these files could take some tinkering with clip attributes and possibly even exports. Camera audio will never be in sync.

In any case, there is no special buffering of braw files; they're instantly available, as with any other codec. Not advisable, but you can even play them in Resolve direct off a memory card. 24-hour buffering can't be the explanation.

Which hardware (CPU, GPU, RAM, disk I/O speed)? What specific version of Resolve? What OS? What source file codec? What timeline resolution? What framerate? How does your drive rate with Blackmagic Speed Test? Which GPU drivers are installed? What proxy format are you using?

M1 Max 64gb Resolve 17 Mac OS 12.3.1 No need for a timeline when doing proxies, frame rate 25fps drive passes all the tests using metal architecture with the BM speed test
proxy format half size H.264, codec is BM raw