Help with external storage behaves strange

Dear All, i have been playing around with FreeNAS and nextcloud for past few weeks and i failed and fed up with my setup. i have a nextcloud plugin based install inside FreeNAS jail and everything works fine but unable to use external storage.

Current Setup
i have mounted my dataset “AllData” to destination /mnt, there are 4 folders inside “AllData” with the same permission (user:www, group:www) and i am able to see 3 folders only inside nextcloud under external storage share. i am able to open those 3 folders but all shows empty even though there are files inside.
it also shows you don’t have permission to upload or create file here
(please see the second image as i can only add two image in a post)

After researching i found that adding external storage from smb share is much better and easy, but i don’t have an option to add smb share. please see below

also there is no app to install “smbclient” under apps too.

i have created a new folder inside the dataset through windows, and created some text files, those files are appearing in nextcloud but nothing else. i found that the files visible inside nextcloud and files not shows have same credentials/ permissions set. please see below

now i am stuck at no where and don’t know what to do. i have added www as the user and group for my pool, i even tried giving everyone having full permission to the same.

please advice , any help will be highly appreciated.

Looking for some help please

Looking for help as I’m stuck at no where. Unable to mount external storage