The search function on the network tab has always said no search results since the network tab was first implemented. It would be great if the search function is about to search through listed network requests contents, starting with the request currently being viewed if one is being shown. Currently, finding request data on a site that makes many requests is extremely cumbersome, requiring you to first search the resource tab, find the relevant code, figure out which request is being made, then locate the request manually on the network tab. If the request for instance is a javascript file that contains some code followed by a very long single line of JSON, you then need to scroll through, possibly hundreds of thousands of characters, of JSON manually until you find the data you are looking for. If you wish to compare multiple similar ajax requests, you need to then locate the next request and manually scroll through the very long line again, looking for the data. As you can imagine, this is a painful procedure and I am surprised no one has noticed this issue in the last few months... While trying to work around the issue, I noticed the Export to HAL option for network requests, unfortunately this does absolutely when clicked on, just like the network search.
*** This bug has been marked as a duplicate of bug 55489 ***