Bad Image capture

[isshin1]

I've using grim+slurp combo to read and get the pixel color using grim -g "$(slurp -p)" - -t png -o which worked well so far, but recently on wayland apps like firefox/nautilus/foot , if I use the above command them on them then most of the time I'm getting is a single black(#000000) pixel regardless of the color.
sometimes with foot, I'm getting wrong colors too other than from black pixel.

weirdly if I take a screenshot and then capture the earlier pixel location from it, using imv, its working properly. Its also working well with electron apps which are still on xwayland

any clue on this ?