Issue with Lookup Multiple Rows Function Not Returning Results

Hey team! Lookup Multiple Rows function in my table stopped working. Simple setup - looking for all emails in the Contact table using the domain from the Accounts table. It was working today and suddenly stopped 30 minutes ago. The original column shows tens of found accounts, but if I rerun it, it shows zero. To test what is going on, I've added a totally similar column - it returns 95% of accounts not found. Please help me to understand what is wrong?