Keynote iCloud: Images larger than 1920x1080 look jagged

Hello,

I’m working with a PNG image (3227×2008 px, with transparency) created in Photoshop. When I import it into Keynote on iCloud, the image always appears jagged even though its resolution exceed Keynote's canvas size which I believe is set to 1920x1080 on the iCloud version. There was one instance where it displayed at its native resolution, at that point the edges looked clean and sharp, not jagged. Although it was good for only an instance (a few seconds) it quickly resorted to a jagged look but I haven’t been able to reproduce it the sharp look since.

For my presentation, I need the image to maintain a higher pixel dimension than that of the Keynote slide canvas so that I can animate it with Magic Move as part of the image must transition in from the bottom to the top.

Question:

How can I import the PNG into Keynote so it retains its native resolution (i.e., no automatic downscaling on import), allowing me to scale and move it smoothly without visible quality loss?

I’ve attached a screenshot for reference.

Here is the scaling in Keynote @ 100% to make sure this is not a point of confusion for anyone reviewing this issue.

[Edited by Moderator]