Including a sequence diagram in layers

[SayChi]

When I include a sequence diagram in a layer from another file, it renders very different from when rendering the sequence diagram itselfs

with a file seq.d2:

shape: sequence_diagram

a: me
b: github.com/terrastruct/d2

a -> b: issue about a bug
a."some note about the bug"

if i'm right: {
	a <- b: fix
}

if i'm wrong: {
	a <- b: nah, intended
}

and overview.d2:

layers {
	seq: @seq
}

I run d2 seq.d2 seq.svg giving a good looking result:

while running d2 overview.d2 overview.pdf results in:
overview.pdf

The svg looks as expected, but the groups get broken in the overview.pdf (I think these groups breaking might also be what cause things to overlap)