Snap to Artboards - double midpoint?

[Harry]

It seems like there are two horizontal snapping guides for artboard midpoint - Video

I noticed this problem with large artboards.

[VectorStyler]

@Harry Are there margins set for this artboards (in the Artboard Options -> Margins section)?

[Harry]

@VectorStyler Here are the margins options:

But when I decreased artboard size to 100 x 100 px this problem doesn't exist, but there is an invisible grid set to -4450 px and some rectangular under the artboard:

Here is the VS file:
0_1710373987968_Snap to artboard issue.vstyler

[VectorStyler]

@Harry Found it: it is caused by the bleed (set in the document options). The margins defined by the bleed (and the center of that frame) are also snapping locations.