Hi all,
The ssue is now resolved
In my testing @drwtsn32 mentioned an assumption that Duplicati was running as a Windows service - however this was not the case. I had set it up in user mode for testing and had not yet converted it to a service.
Upon converting from a user process to a service (and waiting the 6 hours for it to rebuild the database) it appears to have resolved the issue.
I now get more warnings (from 34 to 141) of the below nature, however for the last 6 days the backups have run taking only 38 minutes
[Warning-Duplicati.Library.Main.Operation.Backup.FileEnumerationProcess-FileAccessError]: Error reported while accessing file:
I am unclear if it was the change from user process to system service that fixed it, or if it was the rebuilding of the database. But I suggest time will tell. If it was indeed the change to process (assumably from permissions issues) then this issue should be permanently resolved, however if it was he database it will very likely return again after some time
Thanks to @drwtsn32 and @ts678 for your assistance in troubleshooting and should the issue come back I will update this thread further