Steps to reproduce
Prerequisite: User has two devices, each device contains a list with the same name, but articles within each list is different (and sync is not yet active on their account)
On device #1, login to the Wikipedia app with the reading list "My reading list", containing the 3 articles Apple, Banana, and Carrot.
Enable syncing on device #1
Open device #2 which also has a reading list called "My reading list", but this list contains the articles 3 Deer, Elk, and Fox.
On device #2, login to the same account that is active on device #1
Syncing is automatically enabled on device #2
Device #1 and #2 should sync so that the reading list with the same name "My reading list" on both devices will now be comprised of all 6 articles (Apple, Banana, Carrot, Deer, Elk, Fox)
Saved articles update significantly before reading lists