Closed Captioning timing Slipping on MP4 Slide Video

Hi All!

Captivate Build: 11.5.5.5553

I have a 7:30 minute MP4 file placed as a slide video. 

I have added closed captioning using "Edit Video Timing", the script is coming from a Word file. (Yes, did not bother to copy out as an ASCII file which may explain another issue.)

As the video playback progresses, the CC gets more and more out of synch. I don't have this problem with audio as a separate file, but this issue has surfaced in the past using MP4 files. But I don't remember how (or if) I resolved this time slippage. 

I do recall in the past spending a large amount of time resetting the CC flags, but the CC would still slip.

I _could_ I guess split out the video and the audio as two separate files but then I am concerned about losing voice synch.

Next question is, my CC text color is not changing. I prefer white text on a black background, and while the CC options will change the background, and I can _resize_ the text, the _color_ of the text does not change. I am guessing this is  a holdover attribute from Word, but I would prefer to not have to re-enter all the CC I have just pasted in.

Or am I overthinking this? Is there a way to attach an SRT/VTT file to Captivate I have not tumbled to? I do have a well-timed YouTube-generated caption file but I am using that as the source for my copy/paste manual CC addition.

As always, my appreciation for any thoughts!