Files called "Icon" pollute folders in shared cloud services Dropbox and Google Drive

Hi,

I'm currently testing the Parallels 16 trial. On my macOS 10.15.6 host I'm running Google Drive Files Stream, iCloud Drive, and Dropbox, which I share with the Windows10 VM for testing Edge and IE11 freely available from Microsoft.

I noticed that numerous folders contain files entitled "Icon", which are normally invisible in the host OS. If I activate the display of hidden files and folders in macOS Finder the files show up as "Icon?". Presumably because the file names contain these non-visible Unicode code points, these are being replaced by a block sign in Windows and by a question mark in macOS. These files also crashed a Windows application called SayMore, when accessing those folders, presumably because of these non-compliant filenames.

How do I stop these from appearing?

Thanks for the support.