Alarming - GPT exhibiting state transfer between sessions

Is anyone else seeing what i am seeing. I uploaded a spreadsheet to a ChatGPT4 session last week and later deleted the session. I started a new session this week and the spreadsheet is still in memory, is in tact and can be queried. I have reproduced the problem multiple times. when starting a new session i can prompt ChatGPT to confirm that its a new session and is stateless but the spreadsheet turns up in /mnt/data time after time.