23.4.0 BETA (Build 37)
Macbook Pro
MacOS 13.2.1 (22D68)
I tried twice with the same results
I finished my rough cut and made a transcript. Then I made captions. This revealed that one of the speakers is missing from the transcript some of the time.
In the attached image, you can see that both speakers have captions some of the time and that sometimes one is missing.
The warning is for a caption that is too big for its bounding box. This is not the case, however.