Add Attachment Cannot See All Folders

I am running Mailspring 1.9.2 via Flatpak on PopOS 22.04. When I go to attach a file in Mailspring, I see the folders Home, Desktop, Documents, and Downloads. Missing are the folders Dropbox, Music, Pictures, Videos, Zotero, etc… If I try and drag/drop a file from the File Explorer from a folder not visible to Mailspring, say from Pictures, into Mailspring, I get an error that Mailspring does not have permission to access this file. I have to move it to Documents then add it.

All of these folders have the same approximate permissions:

drwxr-xr-x  2 school school 4.0K Aug 31 01:20 Desktop
drwxr-xr-x  6 school school 4.0K Oct  4 16:00 Documents
drwxr-xr-x  3 school school 4.0K Oct  3 16:50 Downloads
drwxr-xr-x  2 school school 4.0K Aug 31 01:20 Music
drwxr-xr-x  3 school school 4.0K Sep  1 06:04 Pictures
drwxr-xr-x  2 school school 4.0K Sep 27 12:43 Videos
drwxr-xr-x  6 school school 4.0K Sep 23 22:58 Zotero