/seen is broken for some usernames

Plugin version: 3.4.24
Server type: 'Spigot, Paper, CraftBukkit, etc....'
Server version: Paper

**Describe the bug**
/seen [ign] gives an error for some usernames

**Expected behavior**
To give the correct info

**To Reproduce**
/seen [ign]. Only happens on some usernames

https://paste.tws.gg/?804b52b121589f6d#HAa3cs9CfDxbzP2tZsGBF1hddBD6D1uQK5bg9Mdn4mE
