Hi,
Which type of email account are you using? Exchange, IMAP or POP3?
How many email account do you have in your Outlook? Does this issue happen when searching in each email account?
Do you have any update installed (Office update or Windows update) recently?
Please try using the Inbox repair tool to scan and repair your Outlook data file and then see whether this issue continues. For your convenience:
https://support.office.com/en-gb/article/Repair-Outlook-Data-Files-pst-and-ost-25663bc3-11ec-4412-86c4-60458afc5253
Besides, we may also try to rebuild your Outlook index and then test it again. To do this, exit Outlook, go to Control Panel > Indexing Options, click
Advanced button, then click Rebuild button.
Hope this helps.
Regards,
Steve Fan
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