Apologies for the late reply.
In version 2.33.0 of Filebrowser, the default running permissions were changed. Previously, Filebrowser ran with ROOT privileges, allowing read/write access to files. However, with the updated permissions, it no longer has the ability to modify files.
A helpful user has created a Filebrowser plugin that grants ROOT privileges. You can find it here: .【Add-on Guide】Volume management & Filebrowser add-on - #65 by john.e.dixon
In future versions, we will add an option to adjust the running permissions for add-ons to resolve this issue