'Save as' function broken under Mint with

Trying to save documents to my desktop. Click Save as, pop up box appears, choose desktop, desktop contents open, folder on desktop highlighted. If I click ‘save’ the highlighted folder opens, ditto if there is another folder. Eventually I am allowed to save the document when there are no more folders for the pop up to open. Document is saved 2, 3 or 4 folders in from where I wanted it, the desktop. I can choose other folders, Downloads E.G., and the same thing happens not allowed to save until I reach the bottom folder. Even if I open a document from the (E.G.) Desktop I cannot save it back there with Save As.