@ Pseeb
No, you are not the only one. Finding a prior-year return is one of the common questions in the forum.
For the sake of completeness, since you haven't outright stated, I'll ask you to confirm if your 2023 return was prepared Online, or did you use 2023 desktop software (CD/download?) Any return prepared in desktop TurboTax will not be in an online account. So if you did use 2023 Online TurboTax, here's how you can look further:
I know you said you only have 1 online account, but did you try looking for more than 1 account anyway (see steps below?) We forum users help people in this forum everyday who are adamant that they only have 1 account, and most often they tend to have another. And you said that TurboTax Support finally found something/somewhere so we don't know where they found it.
Perhaps you have already done all of the following, but this is how most people can look for multiple accounts by following the instructions exactly.
To get a list of your User IDs, reset password, and recover account access, etc., you can use the tool at the link below. When using the Account Recovery tool, try using your phone number first if you can still access it. After that, if necessary, then run the tool on your email address(es) you can access. If still unsuccessful, I've also provided below a method that doesn't require phone or email address.
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 can copy this link so you can paste it into the new browser session.
https://myturbotax.intuit.com/account-recovery
If still no luck after running that on your phone number you can still access and email address(es) that you can access, here's another method that doesn't use either:
Do the browser clearing again, close and reopen browser. Then go back to the tool again, but this time leave the data field blank, scroll down a bit, then choose the small blue link that says "Try something else", and it will look you up by other parameters.
