IRS Transcripts Blocked After 570/971 Codes - April Letter Directs to Identity Theft Line Despite No ID Issues

Filed my taxes and had transcript access until today. Now getting blocked from viewing them. I received a letter from the IRS dated 04-26-2024 with Tracking ID: 105881271594 that basically tells me nothing helpful. The letter states: "We apologize for the inconvenience, but we are not able to process the requested tax year at this time. Please note: Transcript requests for other tax years may be available. You or your representative can contact the Identity Theft Toll-free at 800-908-4490 for any tax year that is not available." This is so frustrating because I filed my return for December, 2023 (Form 1040) and had full access to my transcripts until recently. The letter is dated 04-26-2024 and was sent to my address in FREEPORT, TX. I called the IRS and the representative claimed that no one can view transcripts until returns are released - which I know isn't true because I was able to view mine just fine until today! I've had 570/971 codes on my account since March 18th, and I'm clearly stuck in some sort of review process. I've tried everything - contacted my Congressman, reached out to a tax advocate, but nobody has been able to help. I haven't amended my return and I didn't need any identity verification. The letter mentions calling the Identity Theft Toll-free line at 800-908-4490, but I don't understand why they're directing me there when I haven't had any identity theft issues. I'm just stuck in review with absolutely no answers, and now I can't even check my transcript status. Has anyone else experienced this? What should my next steps be?