Online TurboTax saves each time you change screens. You can come and go during preparation. There is a Sign Out link at the bottom of the left menu column, but it will save info even if one were to close the browser or get disconnected. The best way to exit is using the "Sign Out" link.
Is it acting like it wants you to start a new return? Then you likely have multiple accounts without realizing it and signed into the wrong one.To get a list of your User IDs and recover account access, you can use the tool at the link below. Try using your phone number first. After that, if necessary, then run the tool on your email address(es) you can access.
NOTE: Before running the account recovery tool below, log out of all Intuit accounts including this user forum, or you might end up in a loop. Then clear your browser Internet cache, close your browser, then reopen it, and go to the link below. You may wish to copy this link so you can paste it into the new browser session.
If still no luck after running that on your phone number and email address(es) that you can access, here's another method:
Go back to the tool again, but this time leave the data field blank, and choose the small blue link that says "Try something else", and it will look you up by SSN and other parameters.