Cannot drill down through folders when attaching files

Hi,

I have noticed in the last month (the same time that it started opening two versions of attachments as per another thread) that when I am attaching a file I can no longer double click on a folder and drill down to the file I wish to attach. I double click and nothing happens. If I move the file to the root of the drive I can select it and attache it.

I am running Outlook 365 on Mac.

Thanks.