Cannot get Katalon to recognise File Explorer when it is opened

Hi, I have a site that I am testing, that during the process flow, has to go off to File Explorer and select a spreadsheet to upload to the page.
I recorded the process and it is fine, until it gets to the file explorer screen. It opens the window, but then does not recognise anything in it. I have tried to create a new object, but it wont let me. Every time I click in the window, Katalon makes a noise and it doesn’t seem to recognise the window at all, so I have no idea on how to get the findTestObject call to work ? I have tried UploadFile, switchWindow to name a few things, but I cannot get it to work !
Has anyone else had this issue and managed to get it to work ?

did u figure out how ?