Online Files are shown as Zero Bytes

Apologies if this has been discussed before but I couldn't seem to locate anything related in the search. 

As stated in the subject line. My new MAC (I'm still becoming accustomed to) is not reporting the Online Only filesize in Dropbox. 

I have checked off the setting in the online account for 'Online-only files on Mac'  OFF. It was originally set to OFF, I tried both ON and then again OFF again.  

I have closed and reloaded the app and rebooted the Mac. 

Files still report 'zero bytes' in the DropBox Size Column.

The description isn't so clear to me as this setting states;

'This displays online-only file sizes in Mac Finder as zero bytes so you can easily review which files are taking up hard drive space.'

If they display as zero bytes, how would you determine what is taking up space? Likely I'm going down the wrong path?

I use freefilesync to keep data sync'd up across drives and with DropBox. Because freefilesync detects the DropBox file size on the Mac is different than the source files on my portable SSD, 'xxx bytes' vs 'zero bytes', it always want’s to overwrite all. I have .8TB to sync so this isn't an option to do with online files. 

If I select a file to on the Mac to be 'available offline' it will update and report the size accordingly. Setting it back to online reports back as zero bytes. 

On my windows machine, DropBox reports the file size regardless if the file is set to Offline or Online only so no issues syncing my devices with DropBox there. 

MAC

Windows

Thanks in advance.

Shawn