Alacritty / sctk-adwaita not getting pointer input in floating mode

[ids1024]

It seems this is a regression caused by #380.

While tiled, clicking on the close button in Alacritty works correctly. But while floating, the pointer input seems to go to the main surface instead.

[git-f0x]

I've noticed that an area along the top and left edges (width around half of window header) in GTK apps isn't clickable while floating, which makes resizing with the mouse impossible there.
In all apps, the cursor also often doesn't switch back to its default icon when going past window edges (stays using the resize indicator icon).