Audio half second off timing of video? Need help ASAP

Hello,

So I was sent a mp4 to score music, imported into Cubase, got the FPS which is 30, locked video, everything fine in Cubase. Sent audio back to Developers, whenever they align the music it’s half a second late?

What could the isssue be? Obviously locators are correctly set when exporting in cubase. The trailer is supposed to be published tomorrow!

I also tried MediaER/ProResER to replace the audio, but it’s still off.

Thanks!

Also just tried importing to Adobe, the wav is off by half a second and everything is zero’s at frame 1.

Could it be you have plugins on the master that adds latency? Half a second seems a bit much, but I got 45 ms off when I put Sonarworks on the master haha…

Yeah Izotope but that shouldn’t matter. Also, when I send the MP4 back to Poland, and the developer uploads to youtube it’s off somehow. When he views it from his end its off, but it’s on point here in North America. Makes zero sense.

I usually like .mov files for Cubase, could mp4 be an issue?