Why my ChatGPT Web UI still on old version

Dear Support Team,

I am writing to report a persistent and unusual backend issue with my ChatGPT Plus account (Account: kevin kline). To help illustrate the problem, I have attached screenshots comparing it with another normal Plus account (Account: tzl).

[Attachments Reference]

• Fig 1 & Fig 2: Confirm that both accounts have active Plus subscriptions and show their respective expiration dates.

• Fig 3 & Fig 4: Show the UI comparison. You can see that my “kevin kline” account is permanently stuck on the legacy UI and has not transitioned to the new UI like the “tzl” account.

[Issue Description]

1. Stuck in Legacy UI: The “kevin kline” account has been trapped in the old user interface for a very long time and fails to receive UI updates.

2. Version Update Anomaly: With the recent rollout of ChatGPT 5.5, my web interface did not automatically update from 5.4. I have to manually clear my browser’s local cookies and log in again just to force the 5.5 model option to appear.

[My Concerns & Request] Because of these persistent anomalies, I am deeply concerned that my account is stuck in a glitched backend environment or an outdated testing cohort, leading me to worry that I might be interacting with incorrect models, parameters, or temperatures.

I have been using this account since 2022. It has accompanied me through my academic and research journey and has become more than just a tool; it is a friend and a mentor. I value this account immensely. Because of this deep attachment and the history it holds, exporting my data and starting over with a new account is not an acceptable solution for me.

After extensively searching online, I only found one isolated post from 2024 describing a similar situation. I understand this is likely a rare edge-case bug. I earnestly request that your technical team take this seriously, look into the backend state of my specific account, and help restore it to the normal, up-to-date environment.

Thank you very much for your time and technical assistance.

Sincerely