Volume Automation - gremlins and inconsistencies

[parityflux]

I am doing a sound remix on a documentary and I am having difficulties with the mix automation. I have lost confidence in the project file because of the rendering problems I am having. It really feels like a bug, but I haven't reported it yet. Here is my sub-mix and final mix busses:

For my testing I am only exporting FullMix as a stem. I have two very apparent problems, which also leads me to be suspicious of the rest of the mix:
1) There is a final fade-out on the Music sub-bus (MX sub). It gets rendered correctly if I export the last 20 seconds of the program. It does not get rendered correctly if I render the whole program (10 minutes). The end just cuts off. For all of my projects I render using the start-end loop points. I confirmed numerous times that I am not cutting anything off.
2) There is a section in the middle of the piece where the volume automation on the MX sub simply doesn't render. The music is under dialog and if I render the full stem, this section is way too loud. If I select a loop range just in this area, the exported stem is normal.

Things I have tried to seek out the root cause:
1) removed all VCAs (there were a few and I think only 1 was automated)
2) turned all effects off
3) transformed audio tracks that had elastique time-stretching (and some RX11 ARA) into rendered tracks.
4) rendered the MX sub as a stem (segment correct, full 10m length incorrect)

The project itself isn't all that intense. It barely touches my CPU even with low buffers and all effects on. At this point it is all audio (I rendered a few VSTs that I had for sfx).

Has anyone come across this, or have ideas about what might be wrong?

 

[Trucky]

Need more details...
Please post screenshots... automation on MX sub (include routing details), markers and your stem export settings?

 

[js1]

One thing to try is exporting in real time to see if that makes a difference. I had an issue some years ago where my export wasn't correct, but was OK if I exported in real time. Whatever the issue was, it got corrected, and regular exports have been fine for me.

FWIW, I do use a fair amount of automation, and haven't encountered your problem (at least, not yet).

 

[parityflux]

Need more details...
Please post screenshots... automation on MX sub (include routing details), markers and your stem export settings?

OK. I don't know if any of this will explain the issue of it working for segment and not working for the full duration, but at least you will some context:

music bus volume

transport range (hh:mm:ss:ff)

start point (MX fade in not too important here, as the source music stems have their own volume automation)

end point

export dialog

 

[parityflux]

One thing to try is exporting in real time to see if that makes a difference. I had an issue some years ago where my export wasn't correct, but was OK if I exported in real time. Whatever the issue was, it got corrected, and regular exports have been fine for me.

FWIW, I do use a fair amount of automation, and haven't encountered your problem (at least, not yet).

Great idea. I should have thought of this. Maybe subconsciously I didn't want to wait for a 10.5 minute render under deadline conditions. Rendering in realtime fixed both 1 and 2 of my original post. I think it's time to report a bug, because this shouldn't happen for such a simple project. Rendering barely touches the CPU. As expected, in rendering it again offline, the issue reappeared.