I have discovered a bug that I can reproduce easily.
Try this please:
display a collection that has associated one to many relations
access one associated relation that has more than one page of rows
When staying on the 1st page, the search bar is running fine
When navigating to another page, then using the search bar, it does not work any more.
Please have a look at the following video: it shows how it works on the first page of transactions, and how it does not find any result when looking for the same string, if the search is operated from the 2nd page.
You can see that the “page%5Bnumber%5D=2” parameter is passed.
But the count query is returning only 9 rows, so it cannot serve the 2nd page when there is 20 rows per page.
From my point of view, the search query in the first search occurrence, should not ask for the page number of origin.