Hi,
Thanks for explaining the issue. What you're seeing, where contact lists in New Outlook can't find or display contacts is a known problem in recent versions. Just to clarify, when you try to use a contact list, do you get an error, or is it just empty even though your contacts are there? That helps determine if it’s a display/sync issue or something deeper like data not migrating.
Here are a few things you can try:
First, try switching back to Classic Outlook by turning off the “New Outlook” toggle in the top-right corner. This often restores full contact list functionality.
Next, check that your contacts are stored in the default Contacts folder under your main account. If you have multiple accounts, make sure you're viewing the right one.
When composing an email, type the contact list name in the “To” field and press Ctrl + K to force Outlook to recognize it.
Make sure Outlook is up to date by going to File > Office Account > Update Options > Update Now.
You can also try clearing the cache by closing Outlook and deleting everything in this folder:
C:\Users<YourUsername>\AppData\Local\Microsoft\Outlook\RoamCache
If the contact lists were created in Classic Outlook, try recreating them in New Outlook.
Alternatively, Outlook on the web often shows contacts correctly and can be a good workaround for now.Please visit this article, it has a similar issue- https://learn.microsoft.com/en-us/answers/questions/4723944/cannot-create-new-contacts-cant-edit-contacts-cant?forum=outlook_com-outlk_web-outtop_com-outsub_people&referrer=answers
Let me know how it goes or if you’d like help with any of these steps.
Best,
Edward