Hello Mark N, thanks for coming into forums. I'm Myk, an Independent Advisor and I'll be more than happy to help you.
I’m sorry to hear that you’re having trouble with your OneDrive files. Just to confirm, are you checking the files using the OneDrive app? Or it's through the Onedrive.live.com website?
If it's through the app, try to sign in to Onedrive.live.com website, and check if the files are still showing there using a web browser.
If you’re a Microsoft 365 subscriber, you can restore your entire OneDrive to a previous time. You can use “Files Restore” to undo all the actions that occurred on both files and folders within the last 30 days.
- Go to the OneDrive website: https://go.microsoft.com/fwlink/p/?LinkID=251869 (Make sure you're signed in with the correct account.)
- A personal account with a Microsoft 365 subscription, at the top of the page, select Settings: update your profile, install software and connect it to the cloud > Options, and then select Restore your OneDrive from the left navigation.
- On the Restore page, select a date from the dropdown list - such as Yesterday - or select Custom date and time.
- Use the activity chart and activity feed to review the recent activities that you want to undo.
- Note: Before you select Restore, scroll to the top of the activity feed to review all the activities you are about to undo. When you pick a day in the activity chart, the more recent activities are hidden in the feed, but they're still selected when you select an activity.
- When you’re ready to restore your OneDrive, select Restore. This action will undo all the activities you selected.
If you require any further information, then please don’t hesitate to get in contact. I will be more than happy to assist you further.
Kind Regards,
Myk