Sony FX3 HEVC-HS: Audio Sync Lost After Render and Replace (Multiple Seconds Offset) - macOS

[Peter Reef]

I'm experiencing severe audio sync issues specifically when using Render and Replace with Sony FX3 HEVC-HS footage in Premiere Pro. The audio becomes out of sync by multiple seconds after render and replace, despite being perfectly synchronized during normal editing and final export.

Key Details

• Source footage: Sony FX3 HEVC-HS UHD 50p

• Timeline settings: UHD 50p (matches source)

• Render and Replace target: ProRes LT UHD

• Audio behavior: Perfect sync during editing and export, massive offset only after render and replace

• Offset display: Audio offset is visible on clips in timeline after render and replace

• Restore unrendered: Partially helps but doesn't fully restore sync

Steps to Reproduce

1. Import Sony FX3 HEVC-HS UHD 50p footage into Premiere Pro

2. Create UHD 50p timeline (matching source)

3. Verify audio/video sync is perfect during playback

4. Select clips and use Render and Replace with ProRes LT UHD

5. Audio becomes severely out of sync (multiple seconds offset)

6. Use "Restore Unrendered" - sync improves slightly but remains noticeably off

System Specifications

• OS: macOS (latest)

• Premiere Pro version: 25.3.0

• Camera: Sony FX3

• Source codec: HEVC-HS UHD 50p

• Timeline format: UHD 50p

• Render target: ProRes LT UHD

Additional Notes

• Issue is specific to render and replace function

• Normal editing workflow maintains perfect sync

• Final exports from original HEVC-HS files are perfectly synchronized

• Problem appears to be with how Premiere handles audio timing during render and replace process for this specific codec/camera combination

• Issue persists even with timeline settings exactly matching source footage

This seems to be a codec-specific bug with Sony FX3 HEVC-HS files and the render and replace function. Has anyone else experienced this issue or found a reliable workaround?

Expected Result: Render and replace should maintain audio sync
Actual Result: Audio offset of multiple seconds after render and replace

Any help or acknowledgment from Adobe would be greatly appreciated, as this significantly impacts post-production workflow with Sony FX3 footage.

[R Neil Haugen]

Have you tried reverting to 25.2? That has fixed playback lag and oddities for some Mac users.

[Peter Reef]

I didnt, but I hope it will be fixed in the next version. This time I can do without rendering audio..

[Warren Heaton]

As @R Neil Haugen suggested, I'd use Creative Cloud Desktop to roll back to Premiere Pro 25.2.  You'll be able  to open your 25.3 project in 25.2.3 to continue from where you left off.

Or, before using Render and Replace, duplicate the audio to another Audio Track prior to doing Render and Replace.  Then disable the replaced audio and link the original audio via Clip > Link.

[Peter Reef]

currently I dont need the feature so I will stick with 25.3.

If I only need to render and replace image without audio I could just select only video and render and replace but I needed both.