research allies not getting a percentage of the research

What server I think they nerfed it on some solo servers to prevent tech leeching.

It's in one of the announcements for updates (years ago) - solo servers makes it dependent on the tech per turn of both countries. If you have at least half as much, you get the full benefit (e.g. 10%) and it decreases the lower yours is.

Need to add this information to the UI somewhere.