MacBook Pro 16 M1 Max Photos painfully slow.

Seems to be a new problem. Im browsing my photos and they look okay, as soon as I hit "Z" to zoom in 100%, it takes up to 10 seconds for the photo to become clear. What could be the issue? Is my Mac too old all of the sudden? I did do an update recently, could it be indexing? how would I know if it is? Thank you!