List searches do not work: SharePoint stack exchange

We have used searches many times in the past to create a summary of information collected from several other lists. This has always worked very well in the past in our online SharePoint environment.

Starting yesterday, we created a new summary list and will only collect information from one list, but not from others.

I tried it on the site we have been using, created a new subsite and also a completely new site. I created a list with only 3 records and tried to find it and it doesn't work. Does anyone else have this problem or know how to fix it?