Can't find something in the SQL

I need to change 600 works on my website..
For exemple I want to change the H1 tag of this page => https://www.urbangaming.fr/team-building/teambuilding-sur-belgrade/

When I search for the string of characters ( HTML or not), nothing is found in the SQL database.

To make sure everything is clear enough, I create a screencast of my search..
Here it is => https://www.dropbox.com/s/vj6cxurw4jcf84r/problem-search-and-replace.gif?dl=0 ( you have to open it, dropbox doens’t previex animated gif.

For some request on the work it has worked, but for some, it doen’t get any result.

Thanks,

https://www.ads-software.com/plugins/search-and-replace/