Duplicati no longer able to access source folder

Hi, not really sure what’s going on and hoping someone can help.

Duplicati stopped backing up my files at some point, probably a few months ago, but was working fine before. My folder structure hasn’t changed, but I’m wondering if maybe an OS update caused some issues?
I’m currently on MacOS Catalina 10.15.2.

I have Duplicati set to backup from only a single folder, but that folder is actually an AFP (Apple File Share) path on my file server, accessed via the ‘/Volumes/Pictures/’ path (which as noted, was working fine over the past several years but has since stopped working). It seems Duplicati is generating a warning, but it’s obviously no longer doing any actual backing up since it can’t seem to access the folder.

I just gave Duplicati full disk access via System Preferences, but that hasn’t helped. As far as I’m aware it’s running under my main account on my Mac, which has read & write access to that share/path.
Below is the beginning part of the logs (the rest of the logs seem to just repeat the same stuff a few times), hoping someone can help:

DeletedFiles: 0
DeletedFolders: 0
ModifiedFiles: 0
ExaminedFiles: 0
OpenedFiles: 0
AddedFiles: 0
SizeOfModifiedFiles: 0
SizeOfAddedFiles: 0
SizeOfExaminedFiles: 0
SizeOfOpenedFiles: 0
NotProcessedFiles: 0
AddedFolders: 0
TooLargeFiles: 0
FilesWithError: 0
ModifiedFolders: 0
ModifiedSymlinks: 0
AddedSymlinks: 0
DeletedSymlinks: 0
PartialBackup: False
Dryrun: False
MainOperation: Backup
CompactResults:
DeletedFileCount: 2
DownloadedFileCount: 0
UploadedFileCount: 0
DeletedFileSize: 1722
DownloadedFileSize: 0
UploadedFileSize: 0
Dryrun: False
MainOperation: Compact
ParsedResult: Warning
Version: 2.0.4.23 (2.0.4.23_beta_2019-07-14)
EndTime: 2020-01-05 10:06:47 AM (1578236807)
BeginTime: 2020-01-05 10:06:34 AM (1578236794)
Duration: 00:00:12.9740990
Messages: [
2020-01-05 10:05:16 -05 - [Information-Duplicati.Library.Main.Controller-StartingOperation]: The operation Backup has started,
2020-01-05 10:05:24 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: List - Started: (),
2020-01-05 10:05:54 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: List - Completed: (2.81 KB),
2020-01-05 10:05:56 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Started: duplicati-b3fd76b1fa64d4706a9620bbece5eef59.dblock.zip.aes (845 bytes),
2020-01-05 10:06:25 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Completed: duplicati-b3fd76b1fa64d4706a9620bbece5eef59.dblock.zip.aes (845 bytes),

]
Warnings: [
2020-01-05 10:05:18 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileEnumerationProcess-FileAccessError]: Error reported while accessing file: /Volumes/Pictures/,
2020-01-05 10:05:18 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileEnumerationProcess-FileAccessError]: Error reported while accessing file: /Volumes/Pictures/,
2020-01-05 10:05:54 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileEnumerationProcess-FileAccessError]: Error reported while accessing file: /Volumes/Pictures/,
2020-01-05 10:05:54 -05 - [Warning-Duplicati.Library.Main.Operation.Backup.FileEnumerationProcess-FileAccessError]: Error reported while accessing file: /Volumes/Pictures/
]
Errors:
BackendStatistics:
RemoteCalls: 9
BytesUploaded: 1722
BytesDownloaded: 53754375
FilesUploaded: 2
FilesDownloaded: 3
FilesDeleted: 2
FoldersCreated: 0
RetryAttempts: 0
UnknownFileSize: 0
UnknownFileCount: 0
KnownFileCount: 2876
KnownFileSize: 74622481468
LastBackupDate: 2019-10-14 1:41:05 PM (1571074865)
BackupListCount: 8
TotalQuotaSpace: 1099511627776
FreeQuotaSpace: 78871965765
AssignedQuotaSpace: -1
ReportedQuotaError: False
ReportedQuotaWarning: False
ParsedResult: Warning
Version: 2.0.4.23 (2.0.4.23_beta_2019-07-14)
Messages: [
2020-01-05 10:05:16 -05 - [Information-Duplicati.Library.Main.Controller-StartingOperation]: The operation Backup has started,
2020-01-05 10:05:24 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: List - Started: (),
2020-01-05 10:05:54 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: List - Completed: (2.81 KB),
2020-01-05 10:05:56 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Started: duplicati-b3fd76b1fa64d4706a9620bbece5eef59.dblock.zip.aes (845 bytes),
2020-01-05 10:06:25 -05 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Completed: duplicati-b3fd76b1fa64d4706a9620bbece5eef59.dblock.zip.aes (845 bytes),