`overlays` entries are picked randomly

[rindeal]

I've followed the suggestion on https://wiki.gentoo.org/wiki/Project:Repository_mirror_and_CI to edit layman.cfg like this:

overlays  :
    https://api.gentoo.org/overlays/repositories.xml
    https://gitweb.gentoo.org/report/repos.git/plain/repositories.xml

Since then layman is randomly switching between them.

For example issuing layman -r <overlay> 3 times results in picking upstream repo two times and mirror one time.

Is that intended behaviour or a bug?