If you are able to play the video on Pro Tools, but the video does not play on voice talent’s device, you want to first check that the zerotime set for the video on MSX and the start time on Pro Tools matches each other. If they do not match each other, make changes to make them match and that should resolve your issue.
If the zerotimes are set correctly and you are still experiencing the issue, turn off the app completely and restart it.