Synology NAS Plex DVR Write Access

Hello,
I have had a Synology NAS for several years, but just recently set up my Plex server. It runs fine with the movies. I installed the latest 1.7.2 version and am trying to use the DVR function. Every recording fails because it says I don’t have write access. I check in File Station and in Shared Folders and Plex and all the subfolders have been given read/write access. What am I doing wrong?

Thanks,