Bug top of screen cut off at 100% zoom / full size

My overlay Canvas has a 1920x1080 reference resolution size (with UI Scale mode set to "Scale With Screen Size"), my orthographic camera has a size of 5.4, and I'm publishing to 16:9 ratio. My build looks correct in the editor, but not when it's published online -- the top is cut off unless I zoom out to 90%, no matter what I do. Is this a bug? Seems like other people have had this issue and not resolved it, and I don't see any reason why I should be seeing one view in the editor and have it not represent the view that's actually published when it compiles -- this never used to happen, unless I was hard coding pixel resolutions into the publish settings and setting my canvases to pixel perfect (which I'm not).
Any help appreciated. Thanks!

PS: Trying to publish at 1920x1080 rather than 16:9 doesn't change anything.