Try the following to fix this issue:
Go to https://influencer.xsolla.com/ then clear cache and cookies for the website.
Log out and log back in to your Twitch/Twitter/Youtube/Mixer account
Open the https://influencer.xsolla.com/ page again and try to log in using your social media account.
If it works, you’re set! If it doesn’t, take a screenshot and send it to us, we’ll go from there.