Clip colour changed when exporting film file * A burn in subtitle issue..

Hi any help most appreciated..

I have two strongly coloured clips in my project, and up to now I've had no problem with them.

Now however that I've tried to export with burn in SRT subtitles, those two different clips are being somehow damaged/modified. See attached one example.

It's very annoying, I need to send the file asap.. but I can't send it with these two clips in totally the wrong colour.

See attachments. First is the normal one.

If I export without the SRT subtitles the clips are fine.

I did have to use AI software (maestra.ai) to convert the subtitles before I imported them.

I could not find anywhere else to do the conversion I needed to ITT, the format FCPX was demanding, FCXP would not import my subtitles in the format they were in .srt.vtt

Ok I decided to try this.

I exported the Pro Res without subtitles.
I made a new project, dropped that export in there.
Added the SRT to that and exported that project with SRT burned in.
That gave me a file with SRT and without any of the colour issues.

Still curious as to why it was happening in the first place..