Firefox on iOS not syncing with desktop

Saved logins, passwords, history and on bookmarks sync between my desktop and laptop computers perfectly. However, none of the saved data will sync to FF on iOS. It has never worked since I got FF for iOS a few years ago. I am tech savvy and I know what I'm doing but has stumped me. Sync account info is good. I'm logged in in all my devices (including the iphone running FF browse), but nothing. Please help. How do I get FF saved info to sync with my iPhone? Thanks in advance for your help Ose