Those msi transducers are really touchy, there's some utube videos showing how to adjust (level) them so they read the depth while on plane. I found this one which has helped me the most so far.
After watching the video again it appears you're getting a good bottom reading while idling or trolling so your ducer is probably level already, might be getting air bubbles while on plane causing you to lose the bottom on plane. Might need to look into a thru hull 2d transducer for depth at speed. If your dealer installed the unit you might want to ask them about it. I don't think an update will be the fix but that's the first thing alot people seem to suggest with any and every issue.