Question Prefix not working

I have a server with some minigames and cosmetic plugins. And also have a problem.
I have Pex plugin and a problem with it. Why doesn't my prefix exist? But in tab list i have it

There list of my plugins:

1. AdvancedPortals
   
2. AnimatedFrames
   
3. AntiRelog
   
4. ASkyBlock
   
5. AuthMe
   
6. AutoMessage
   
7. AutoSaveWorld
   
8. BlockVersion
   
9. BountyPerks
   
10. bStats
    
11. Chairs
    
12. ChatGames
    
13. ChatGuard
    
14. ChestCommands
    
15. Citizens
    
16. ClearLag
    
17. CommandNPC
    
18. CreativeLimiter
    
19. CustomJoinItems
    
20. DonateJoin
    
21. Essentials
    
22. FastAsyncWorldEdit
    
23. Friends3_0
    
24. HolographicDisplays
    
25. ItemFixer
    
26. Jobs
    
27. MapManager
    
28. Marriage
    
29. MineResetLite
    
30. MultiMOTD
    
31. Multiverse-Core
    
32. Multiverse-Portals
    
33. MultiWorld
    
34. NoCheatPlus
    
35. Parkour
    
36. PartlyFancy
    
37. Passport
    
38. PermissionsEx
    
39. PerPlayerBlood
    
40. PluginMetrics
    
41. ProtocolLib
    
42. RandomBox
    
43. RandomPort
    
44. RPGHealthIndicator
    
45. ServerProtector
    
46. SkinsRestorer
    
47. sTablist
    
48. SystemBoard
    
49. UltraCosmetics
    
50. Vault
    
51. WClans
    
52. WGExtender
    
53. WorldEdit
    
54. WorldGuard

 

Like this?

https://pastebin.com/FzJEJQZu