Audio playback wrong speed on imported video

I have attached a (large) video to a Dorico file. The video is playing back at the right speed, but the audio is playing back very fast (squeaky voices Pinky and Perky-style). I have tried with a couple of different films, and re-started a fresh Dorico project.
Is there a setting I don’t know about to fix this? It is my first time writing to video in Dorico.
Here is a demo of what is happening:

Thanks, Bernard

This is normally caused by a mismatch between the sample rate that was in use when you first attached the video, and the sample rate currently chosen in Edit > Device Setup. Try detaching the video, then renaming it on disk so that it has a different filename, and try re-attaching it.

Brilliant - thanks as ever Daniel