This is due to the search box web part automatically connecting to the search results as part of that webparts default behavior. Unfortunately from the search results web part you cannot disconnect this it seems. I have also tried unchecking the allow connections to try to disable this.
Ultimately it came down to JavaScript when I was trying to find an answer for this. I thought I could just use a Script Editor however those are not available for My Sites and even if you import from a regular site the webpart schema, the JS will not run.
Thus, editing the Master seems to be the only way to do this. Add the following JS near the bottom, perhaps just before body.
<script type="text/javascript">
Sys.Application.add_load(stopInplaceQuery);
function stopInplaceQuery(){
var searchInputBox = $find('ctl00_PlaceHolderMain_searchInputBox_csr');
if(searchInputBox != null && typeof searchInputBox != "undefined"){
searchInputBox.set_tryInplaceQuery(false);
console.log("Stopping inplace query");
}
}
</script>
Note that my code is using a set_tryInplaceQuery
which disables the request to try a local search results webpart. This is actually a property on the master control for that search box, however it seemed to not have any effect there:
<SEARCHWC:SearchBoxScriptWebPart runat="server" id="searchInputBox" DefaultDropdownNodeId="1001" ServerInitialRender="true" UseSharedSettings="true" ChromeType="none" EmitStyleReference="false" __WebPartId="{E4F08BB7-F5FD-453F-B9EF-E682D7403FAA}" TryInplaceQuery="false" />
The JS code I provided may need testing, I am not sure how safe it in terms of executing at the right time. It may need some script on demand additions it you find that it works intermittently.