Audio/Sync Issues

Hello,

I have a very frustrating issue only come to light lately.

Basically, I'm a drummer and I've been uploading drum cover videos for years without problem, same process as below. Same routine every time. Drum audio recorded in logic pro and video recorded on samsung s10 lite phone at 30fps but editing the 2 together in Final Cut Pro X.

In the last 2 weeks I've uploaded several videos thinking all was ok. But! Massive problem seemingly. My audio/video is out of sync depending on where you view said videos. Sync is kinda, ya know... important! 🤷‍♂️

E.G:

• Video 1 (recorded on samsung s10 lite at 30fps 1080p)

• Video transferred via usb cable and imported into final cut pro x on macbook pro.

Drums and track Audio (mixed in logic pro x and exported as 48kHz .wav file ) also imported into Final Cut where I line up both files and "make" my final product. Perfectly in sync. Looks great. This is where I always had my finished product and was happy.

I export this video to desktop as H.264 .mp4 format in 30fps, audio is 48kHz AAC (Perfect for instagram as per their recommended settings) and check it again. Perfect. Happy with how it's synced up and looks. Transfer it back to my phone via usb to upload to Facebook and Instagram profiles. Plays back fine in my android phone gallery too. All good 👍

Upload to Facebook and Instagram:

Herein lies the problem! From this point the hard work spent on audio and video sync goes out the window. Instagram makes an absolute mess of my work. Drums and audio can be upto 2secs out of whack by the end of the video especially on an IGTV full length 😬😬 facebook is the same.

Youtube however, works flawlessly with same file just like if I played the file back off my desktop. 🤨

Now I've been trying to find out why this is happening.

I decided to try uploading to Facebook from my laptop on safari and play it back on safari browser, same problem exists. I open my profile on google chrome, play video and problem is gone, perfect again?? Howww?

I went back and checked 3 previous cover videos on my facebook account on the macbook, sync is non existent. BUT...On my android phone it's fine and my partner's android also so i thought they were fine until a friend said they are out of sync. Turns out he's watching them on facebook on an iPhone🤦 Embarrassing to say the least. So Instagram/facebook is a no fly zone at the moment until I find out whatever is causing this.

I researched VARIABLE FRAME RATE and realised phones unfortunately rely on vfr which can cause audio sync problems/drift and decided to put the video through Handbrake to convert it from variable to constant 30fps frame rate.

Tried all of the above processes from scratch again, same exact problems 😪😕

I'm about to lose my mind because I need these videos looking good on EVERY browser/device not just the ones I know work well.

Sorry for long post but there's surely a way to get this working correctly for online playback staying in sync?

It's the 21st century and nobody has offered up any solutions on reddit forums or anywhere else that I can see where others have this issue. Is it all Instagram and Facebooks fault or am I missing one little detail to make my videos shine on their platforms?

So all in all:

Macbook quicktime playback from desktop: Perfect

Youtube on safari/android/iOS: Perfect

Instagram app android/iOS: out of sync

Facebook safari: out of sync

Facebook Chrome: Perfect

Android Facebook: Perfect

iOS Facebook: out of sync

To me it's looking like an apple iOS/instagram/facebook issue?

Anyone know what is going on? Am I missing something small in final cut??

Thanks in advance. Any help greatly appreciated! 🙏