Keynote Keynote 14.2 will not handle video properly with Alpha channel

I was perplexed when I used my old MacBook Pro 15" 2017 and old Keynote, which has a Red Curtain HD Keynote (opening and closing effects) with an Alpha channel. I have a new MacBook Air 15" with macOS 15 Sequoia and Keynote 14.2 at the latest. I couldn't able to get a Transparent. I even pulled out .Mov files out of the content file .Key

I use FCP to convert it to Apple ProRes 4444 and save it. It works with others well, but Keynote will not work with Apple ProRes 4444 

Is there any solution or recommend?

Thanks

Jeff