A creator posts one partnership link to Instagram, TikTok and YouTube on the same day. Tag it once with the creator's name as the source and your reports can't say which platform sent the clicks. Tag it three times with the platform as the source and each version lands where GA4 expects that platform. instagram and tiktok are on Google's social list. youtube is on its video list, but with utm_medium=social the YouTube version still matches Organic Social, which GA4 checks before Organic Video. Give all three the same utm_campaign, so the partnership reports as one campaign, not three.
Google's shorthand for Instagram isn't on Google's list. Google's URL builder advice suggests a distinct source per sub-platform, with fb for Facebook and insta for Instagram. fb is on the social source list. insta isn't: the list has instagram, instagram.com, l.instagram.com and ig. With a medium of social the gap doesn't matter, because the medium alone meets the Organic Social rule. With paid_social it does. Paid Social needs a listed social source, so utm_source=insta&utm_medium=paid_social falls to Paid Other. Use instagram or ig.
Some guides use a medium called influencer. They set utm_medium=influencer on every creator link, and no GA4 rule names it. With a listed platform as the source, the click still reaches Organic Social, but so does a paid boost tagged the same way, and paid and unpaid creator traffic end up in one channel. With a source that isn't listed, such as insta or a creator's name, it matches nothing and lands in Unassigned.
Creators paid per sale are affiliates. Even so, a creator link with instagram as the source and affiliate as the medium lands in Organic Social, because GA4 checks that rule first. The affiliate UTM builder covers tagging those links by partner instead.
You can give creators one row. To see creator traffic together, set up a custom channel group, which GA4 keeps under Admin, Channel groups. A channel can match on campaign name, so start every partnership's utm_campaign with the same prefix, such as creator-, and one condition catches them all. GA4 files traffic in the first channel it matches, in the group's order, so drag the creator channel above Organic Social. Google says custom channel groups can be applied to reports retroactively, and a standard property gets two of them besides the default. For the Instagram side of the setup, see the Instagram UTM builder.