Catalina upgrade has made files on external hard drive read only
I have a Toshiba Canvio Connect external hard drive that holds both Windows and Mac files using Tuxera (from what I can detect. This is not my area of expertis at all!) but on upgrading to Catalina the files on the external hard drive have become read only and I can't make changes to a file and save to the external HD. I have to save to iCloud. I've also lost one Excel file in the process. I am now running latest Tuxera on a 'trial' so that I can open the files on the External HD. Am I going to have to buy a new external hard drive and transfer across the contents from the 'old' external HD to make the viewable and alterable on an on-going basis?
MacBook Air 13", macOS 10.15