After the 15 minutes, have you tried a different browser to see if that makes a difference?
If still unsuccessful, if you using a paid version of TurboTax (PLUS or higher), you can phone TurboTax Support for assistance:
https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632
Hours are currently 5AM-9PM Pacific (8AM-12 Midnight Eastern) during this last part of extended filing season. So disregard the hours mentioned in that FAQ.