Dear @John John Pter,
Thank you for posting your question in the Microsoft Q&A forum.
As a moderator, I don't have the tools to investigate your specific account directly because this is a user-to-user support forum. Moderators and contributors, including external Microsoft employees, cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas. However, I will try my best to guide you as clearly as possible.
Since I can't investigate your account directly to pinpoint the exact cause, I’m curious that have you tried using an alternative method to export the data from the site yet?
You could try opening Excel > Data > Get Data > From Online Services > From SharePoint Online List. Paste your site URL there, select Implementation 2.0, and Sign in with your Office 365 account. Then click Connect. A window will appear listing all the lists on that site; find and check the box next to your list name, click Transform Data, and check how many expired items show up there.
In the meantime, since this issue requires a deeper investigation, especially given the large volume of data, I suggest reaching out to your Global Admin. Ask them to submit a support ticket in the Admin Center to contact the Microsoft technical team. They have the tools to access your account, investigate the root cause, and help you export the data without missing any items.
Please ask your Global Admin to follow this reference to submit the ticket: Get support - Microsoft 365 admin | Microsoft Learn
If you’re unsure who the Global Admin is within your account's organization, you can find guidance on locating them here: How do I find my Microsoft 365 admin? - Microsoft Support
Keep me updated! I’d love to hear more from you so I can learn and discuss more about SharePoint together.