Level 1

8 points

FCP 12.3 timeline issue loosing audio feedback on the timeline.

Is anyone else having final cut pro 12.3 issues with the interface while editing audio / video? I am prioritizing the audio over the video due to the audio content that I want to edit for Spotify, Apple Podcasts, etc.

I place the video clip in the timeline and begin editing. I am taking out breaths, lip smacks from the speaker, etc. and then adding transitions to the video to make it coincide.

Within 2 or three clips, I loose audio and the timeline does not keep up with the video. The inspector is moving the video along, but I loose all audio feedback. If I hover over the audio sources in the inspector I have audio, back to the timeline - nothing. I have to restart FCP. It does preserve the edits I have made, but it is so laborious.

I thought at first it might be a conversion issue because when I started with the update 12.3, I was midstream in a project. So I started a brand new project with FCP 12.3 and I have exactly the same results.

Exports seem to work ok from the completed projects, but as is it is almost untenable.

I did delete and reinstall FCP and I am running on a MacBook Pro M5 Pro.

Thanks in advance.

Any thoughts?

Posted on Jul 5, 2026 1:27 PM

29 replies

AlertSense Author

Level 1

8 points

Jul 5, 2026 7:45 PM in response to BenB

Thank you for responding.

I edit to an external Sandisk ssd and it is formated with APFS. There is 2TB of free space. I often copy my libraries to an external 20TB spinning disk to free up space. The specs on my SSD are as follows:

SANDISK 4TB Extreme PRO Portable SSD - Up to 2000MB/s - USB-C, USB 3.2 Gen 2x2, IP65 Water and Dust Resistance, Updated Firmware - External Solid State Drive - SDSSDE81-4T00-G25,Black

I will delete all render files and give that a shot. I am editing mp4 files.

AlertSense Author

Level 1

8 points

Jul 11, 2026 12:39 PM in response to terryb

So the video folder is under my account /user/[username]/movies/Roz Temp Libraries.

I don't see that it is included in the iCloud Drive folders that are backed up. I use this directory as I product and then move the FCP library off my HD.

tontoe

Level 1

20 points

Jul 24, 2026 5:09 AM in response to BenB

BenB wrote:

I'm just gonna throw in the towel now and say that 12.3 has several important bugs. I hope we have a fix really soon.

Thank you!

Well put!

Audio drifting out of sync was never a problem with previous iterations, but now it is and my workflow is exactly the same - Multicam with separately recorded audio.

I know I'm relatively inexperienced, so it's great that a level 6 contributor is kinda validating that experience :)

AlertSense Author

Level 1

8 points

Jul 5, 2026 7:57 PM in response to terryb

Ok, I just did that and brought in a m4a file and it is still doing the same thing.

AlertSense Author

Level 1

8 points

Jul 5, 2026 8:05 PM in response to AlertSense

Additional info. Once FCP gets in this state the timeline advance (space bar), visually does not move, but the inspector shows that it is advancing, just no audio and no movement on the timeline.

AlertSense Author

Level 1

8 points

Jul 6, 2026 5:51 PM in response to terryb

No, I am using my MacBook Pro's speakers. I have a MacBook Pro M5 Pro that I purchased 2 months ago. It was working great until this update.

BenB

Level 6

13,670 points

Jul 6, 2026 6:06 PM in response to AlertSense

I'm just gonna throw in the towel now and say that 12.3 has several important bugs. I hope we have a fix really soon.

AlertSense Author

Level 1

8 points

Jul 7, 2026 6:41 PM in response to terryb

Here is the report. Sorry, I had to learn how to do it.

Report.

AlertSense Author

Level 1

8 points

Jul 10, 2026 8:25 PM in response to terryb

No, I am storing them inside my video folder in my account. I do have an external SSD that I was using, but I have started a new project on the laptops internal SSD HD. Still the same results.