JollyRoger:
Have you rebooted the router and modem lately and restarted your computer?
Shutdown the computer, then the router, then the modem.
Wait a couple minutes, and restart the modem.
Wait a couple minutes and restart the router.
Wait a couple minutes and restart the computer.
These things are hard to troubleshoot, since there are so many customizations that people can do to browser settings, cookies (enabled?), browser add-ons, browser extensions (such as content blockers, script blockers, etc.), firewall settings, antivirus settings, VPNs, etc.
A couple of quick things to try:
If you are using wireless, disconnect your computer from wireless, and try a wired Ethernet connection if possible, to see if that makes a difference.
After you launch your browser, open a private window (aka private browsing, incognito mode, etc.) before going to Online TurboTax and logging in.
