Premiere Pro 2022 Exporting to H.264 Problem

I've recently completed a wedding edit and it's now ready to deliver to my client. I've edited/colour graded the piece within Premiere and exported using the same settings that I've always used. The preview of the render when exporting shows a clean and correct image but once the file has competely exported I try to open it and it says "The file contains some media that isn't compatible with QuickTime Player". It still opens the file but the quality of the video is awful and it has a horrible red/pink hue to a lot of the video.

I've attached a photo of what I can see within Premiere Pro and what it looks like after export.

Currently I've tried -

- Switching off maximum render qualities

- Exporting in different file formats (.mov, .mp4)

- Tried opening the file in an old version of Premiere but says it cannot be opened on older versions

- Created a new sequence and copied across the timeline to see whether it was the sequence that was corrupted.

- Opened on my iMac (2019) and my brand new Macbook Pro (2021) to see if that changed anything.

None of these have worked so far.

Any help with this would be much appreciated, I need to deliver this to a client asap.