Access of app to read and write - Administrator cannot change access

Hey, please take a look at this code and tell me why it does not want to save file. Script is giving me an error that I do not have access to file. Error suggest that I need to change the mail access to read and write. After I open mail app -> information, previously unlocking the lock, I cannot add access, cannot change it and Sonoma showing error that I cannot change setting since I do not have access.

Mail app has full disc access, as well as script editor and terminal.

set acc_name to "TEST"
set sender_email to "andrew"
set email_subject to "Test"
set download_folder to (POSIX file "location") as string
set python_script to "location2"

using terms from application "Mail"
	tell application "Mail"
		if not it is running then activate
		repeat with aMessage in messages of mailbox "Alpha" of account acc_name
			
			set client_sender to sender of aMessage
			set client_subject to subject of aMessage
			set client_attachment to name of mail attachment of aMessage as rich text
			set attachment_file to mail attachment of aMessage
			
			if client_sender is sender_email and client_subject is email_subject then
				
				--set noti_text of subject of aMessage
				display notification (client_sender & " " & client_attachment) as rich text with title client_subject
				tell application "Finder"
					delete (every item of folder download_folder)
				end tell
				--set attachmentPath to open for access download_folder & client_attachment with write permission
				--close access attachmentPath
				6
				save attachment_file in download_folder
			end if
		end repeat
	end tell
end using terms from

I am starting to think that it might be system error, not script issue.