Relationship breaks when put in grid

This is a bit convoluted so bear with me.

Basically we have 2 types of widget. They’re Features and Icons, each with their own channel. They each also have Group channels where you can group Features or group Icons. Makes sense so far right? The Groups have titles and descriptions as well.

Pages on the site have Relationships to the groups, so you can have a group of Features and/or Icons on the page. If we have this relationship directly on the page, both work fine.

Having the groups directly on the page is not what we want though. What we’re trying to do is have them in a Grid. On each row of the Grid you can choose what you want on the page via a realtionship field that targets the group channels for Features, Icons or other stuff. If you choose Features Group it works fine, but if you choose Icon Group it fails.

The Icon group only renders out the title an description, but the list of selected icons appears to be empty, it doesn’t get iterated (even putting just “Hello” or whatever inside the loop won’t give you anything, let alone the contents of each icon.)

Move it back out to use the Relationship directly on the page, and it works fine. We’ve scoured over and over for dumb mistakes or typos and there’s nothing, it just seems to be some bug in EE but we also examined the Trees that get generated for the page, and those seem fine too. Any idea where things might be breaking down?

We are running EE 2.10.2 and PHP 5.6

Thanks.