When using multi-networks, other networks image url not working

When using avatars in a multinetwork environment (https://wordpress.org/plugins/wp-multi-network/), avatar link on other networks dont resolve. The avatars are uploaded correctly, the image url is also pointing correctly, but the main-network-site image URL gives a 404 (not found). On the main network the user image seems to be showing and sub-site admin pages are showing up.