Discounts through partnered institutions are activated when you launch and begin your TurboTax return through that institutions link.
If you already started your return, you might try this:
- Save and Log out of your return
- Clear browsing history and cache on your browser, then reopen it or launch a different browser
- Go to Mint and select the tax link within
- Log into your account and check fees.
- My Account>Tools>My Fees