Why did my iPhone contact names disappear?

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Tags

1. #apple
2. #contacts
3. #caused
4. #still
5. #delete
6. #syncing
7. #restart
8. #worry
9. #icloud
10. #losing
11. #iphone
12. #anything
13. #choose
14. #missing
15. #toggle
16. #settings
17. #between
18. #issue